tag:theconversation.com,2011:/us/topics/indoor-plants-6197/articlesIndoor plants – The Conversation2023-04-11T01:41:55Ztag:theconversation.com,2011:article/2021972023-04-11T01:41:55Z2023-04-11T01:41:55ZOwning houseplants can boost your mental health – here’s how to pick the right one<figure><img src="https://images.theconversation.com/files/518448/original/file-20230330-390-mpih7w.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3637&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some houseplants are better than others at lifting our spirits.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-buying-flowers-pushing-shopping-cart-2240764423">adriaticfoto/Shutterstock</a></span></figcaption></figure><p>In both <a href="https://academic.oup.com/bjd/article/164/4/848/6642849">Europe</a> and the <a href="https://pubmed.ncbi.nlm.nih.gov/11477521/">US</a>, people spend up to 90% of their time indoors. But spending so much time inside can have consequences for your mental health. </p>
<p>The <a href="https://www.who.int/news-room/fact-sheets/detail/depression">World Health Organization</a> estimates that 5% of adults globally suffer from depression. Stress, depression and anxiety also accounted for <a href="https://www.hse.gov.uk/statistics/dayslost.htm">55% of all working days lost</a> in the UK during the year 2021-22. Small improvements in our mental health can bring significant personal and financial rewards. </p>
<p>For those of us who are stuck inside all day, houseplants are an easy way of connecting with nature. This is particularly true for young people, many of whom may lack access to a garden. </p>
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<img alt="Quarter life, a series by The Conversation" src="https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><strong><a href="https://theconversation.com/uk/topics/quarter-life-117947?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">This article is part of Quarter Life</a></strong>, a series about issues affecting those of us in our twenties and thirties. From the challenges of beginning a career and taking care of our mental health, to the excitement of starting a family, adopting a pet or just making friends as an adult. The articles in this series explore the questions and bring answers as we navigate this turbulent period of life.</em></p>
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<p><em><a href="https://theconversation.com/taking-a-mental-health-day-can-be-good-for-you-heres-how-to-make-the-most-of-one-186493?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">Taking a mental health day can be good for you – here’s how to make the most of one</a></em></p>
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<p>Indoor plants have several mental and physical health benefits. <a href="https://www.mdpi.com/1660-4601/19/12/7454">Research</a> has linked houseplants to reduced stress, lower blood pressure and an improved state of mind. And office environments with plants have been associated with <a href="https://journals.ashs.org/hortsci/view/journals/hortsci/43/1/article-p183.xml">higher job satisfaction</a> and <a href="https://journals.ashs.org/horttech/view/journals/horttech/10/1/article-p46.xml?tab_body=pdf">reduced health complaints</a>.</p>
<p>Houseplants make us feel good due to our <a href="https://books.google.co.uk/books?hl=en&lr=&id=GAO8BwAAQBAJ&oi=fnd&pg=PP6&dq=biophilic+hypothesis&ots=pmuhMDJYpY&sig=Isej07-3fU9I1po3uX4k9UoANgI&redir_esc=y#v=onepage&q=biophilic%20hypothesis&f=false">inherent desire to connect with nature</a>, and because we consider the <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1002/col.20597">green colours</a> of most houseplants to be calming. Adding just a single plant can brighten up a dull space and boost your mood. But which should you choose?</p>
<h2>Lush greenery</h2>
<p>Last year, with colleagues from the University of Reading and the <a href="https://www.rhs.org.uk/?utm_source=google&utm_medium=cpc&utm_campaign=17599895670&utm_adgroup=136955025566&utm_term=royal%20horticultural%20society&utm_content=606881667002&gclid=CjwKCAjw5pShBhB_EiwAvmnNV_qUwNLOrsD3tEjHXSaMKiNnY6T0tJU9zURAIIgo-u5O5csx52SepRoCOYMQAvD_BwE&gclsrc=aw.ds">Royal Horticultural Society</a>, I investigated the <a href="https://www.sciencedirect.com/science/article/pii/S0360132322003882#bib41">psychological responses</a> of 520 people to the appearance of different houseplants through an online photo-questionnaire. Participants viewed 12 photographs of plants in various different shapes, and answered questions based on their opinion of the plant’s appearance. </p>
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<a href="https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The houseplants assessed by study participants." src="https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=288&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=288&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=288&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=362&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=362&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517263/original/file-20230323-28-apwr4h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=362&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The houseplants assessed by study participants.</span>
<span class="attribution"><a class="source" href="https://creativecommons.org/licenses/by/4.0/">Jenny Berger</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>The participants identified their favourite and least-favourite plant. They then used scales comprising six pairs of contrasting adjectives to score different aspects of each plant’s appearance. They also rated how beneficial they perceived each plant to be for wellbeing and air quality. </p>
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<a href="https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A pothos plant on a wooden shelf." src="https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518440/original/file-20230330-14-h3qw7u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Pothos (pictured), weeping fig and palm delivered the greatest sense of wellbeing to participants.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/beautiful-satin-pothos-plant-on-wooden-1318173557">Rattiya Lamrod/Shutterstock</a></span>
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<p>The eight plant species included in our study were: <a href="https://www.thespruce.com/grow-weeping-fig-indoors-1902440">weeping fig</a>, <a href="https://www.rhs.org.uk/plants/16430/sansevieria-trifasciata/details">mother-in-law’s tongue</a>, <a href="https://www.rhs.org.uk/plants/types/cacti-succulents/houseplants">cactus</a>, <a href="https://www.rhs.org.uk/plants/119598/maranta-leuconeura/details">prayer plant</a>, <a href="https://www.thespruce.com/grow-asplenium-nidus-ferns-1902716">bird’s nest fern</a>, <a href="https://www.rhs.org.uk/plants/32104/epipremnum-pinnatum-aureum/details">golden pothos</a> (or devil’s ivy), <a href="https://www.rhs.org.uk/plants/31916/dracaena-marginata-(v)/details">dragon tree</a>, and <a href="https://www.rhs.org.uk/plants/types/trees/palms-exotic">palm</a> – both as a healthy and neglected plant. Each of these plants are found in homes and offices throughout the UK.</p>
<p>Overall, participants perceived that all green and healthy plants would benefit their wellbeing. But three plants in particular – pothos, weeping fig and palm – were believed to deliver the greatest sense of wellbeing. These benefits improved as plant attractiveness increased. In contrast, unhealthy plants were perceived negatively. </p>
<p>Our findings suggest that plants with lush green leaves, high leaf area and dense canopies are likely to give the biggest boost to your wellbeing. People also believe that these plants will provide greater benefits to air quality. </p>
<p>So, to keep plants looking attractive, consider purchasing those that are easy to maintain such as mother-in-law’s tongue, <a href="https://www.rhs.org.uk/plants/19185/zamioculcas-zamiifolia/details">zamioculcas zamiifolia</a> (commonly called the ZZ plant), pothos, or a <a href="https://www.rhsplants.co.uk/bomcard/_/chlorophytum/chlorophytum-comosum-variegatum-spider-plant-and-pot-cover-combination/classid.2000028188/">spider plant</a>. These can all tolerate a range of conditions and require little watering. </p>
<h2>Leaf shape</h2>
<p><a href="https://journals.sagepub.com/doi/abs/10.1111/j.1467-9280.2006.01759.x?journalCode=pssa">Psychological studies</a> have shown that curved objects elicit positive emotions in humans. Our research demonstrates that these outcomes also apply to houseplants.</p>
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<a href="https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dracaena flower in a ceramic pot standing on a table." src="https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518444/original/file-20230330-21-ias6u3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The dragon tree was less preferred by participants.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dracaena-flower-ceramic-pot-stands-on-2023017578">Elena Medoks/Shutterstock</a></span>
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<p>Plants with rounded leaves such as weeping fig and pothos, or palm with its gentle arching canopy shape, were seen by participants of our study to be more beautiful and relaxing. Some plants, including palm, also evoked happy memories. This is because they are often associated with holidays or tropical destinations.</p>
<p>Plants with spikes, narrow pointed leaves and sparse canopies, such as cactus and dragon tree, were less preferred. This is possibly due to the association of sharp edges with danger. </p>
<p>However, sharp features can sometimes be advantageous. <a href="https://www.sciencedirect.com/science/article/pii/S0272494416300330">One study</a> shows that houses surrounded by sharp-leafed plants were more expensive and evaluated as safer than houses surrounded by round-leafed plants.</p>
<h2>What do you want from your plants?</h2>
<p>Ultimately, the right houseplant for you depends on what you need it for and your room’s conditions.</p>
<p>Humans generally prefer looking at shapes which the brain can <a href="https://academic.oup.com/edited-volume/35428/chapter-abstract/303190946?redirectedFrom=fulltext">recognise quickly and process easily</a>. When seeking a calming effect, choose plants that are sufficiently interesting to attract your attention – such as the pothos with its trailing vines – but select plants with striking patterns and bold colours in smaller numbers.</p>
<p>Plants with a dramatic appearance would be more appropriate as “feature plants”, to generate a focal point. Grouping different plant shapes and colours together in arrangements can further generate interest, while choosing decorative pots or planters can enhance the effect even more.</p>
<p>When deciding on the number of plants required for maximum benefit, more is not necessarily better – a single, carefully chosen houseplant may be all we need to lift our mood. <a href="https://www.sciencedirect.com/science/article/pii/S027249440290232X">Research from Japan</a> found that the presence of leafy plants can enhance creativity in workplace tasks. But, if you are undertaking a task that requires focused attention, too many plants may prove a distraction.</p>
<p>Houseplants can benefit our mental health. But when choosing between plants, their appearance matters. For the biggest boost to your wellbeing, key aspects to consider are physical appearance, interestingness, beauty, and how healthy the plant looks. Keeping your plants green and healthy will help lift your spirits, so choose plants suited to your space that you can maintain easily.</p><img src="https://counter.theconversation.com/content/202197/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jenny Berger does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Houseplants can lift our spirits – but not all plants have the same effect.Jenny Berger, Post-Doctoral researcher, University of ReadingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2028512023-04-06T06:53:19Z2023-04-06T06:53:19ZI’ve created a monstera! How to care for the ‘Swiss cheese plant’ in your life<figure><img src="https://images.theconversation.com/files/519436/original/file-20230404-22-rx2hys.jpg?ixlib=rb-1.1.0&rect=0%2C45%2C5853%2C3872&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>When I was growing up monsteras (sometimes known as monsteria) were not all that common, but neither were indoor plants. In fact, monsteras were out of fashion back then – but now monsteras are back and, appropriately, in a big way.</p>
<p>The plants that we know as monsteras, fruit salad plant or Swiss cheese plants (due to their holey leaves) are a rainforest plant called <em>Monstera deliciosa</em>. </p>
<p>They’re originally from Central America, around Mexico, but their iconic large leaves can now be found everywhere in popular culture – from fabric prints and earrings to tattoos and mugs.</p>
<p>So, what’s special about this large and lovely plant? And what’s the secret to keeping one happy and healthy?</p>
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Read more:
<a href="https://theconversation.com/multi-coloured-plants-are-suddenly-a-home-decor-must-have-heres-how-to-keep-them-alive-181163">Multi-coloured plants are suddenly a home decor 'must-have'. Here's how to keep them alive</a>
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<h2>Rainforest climbers</h2>
<p>In their natural habitat, monstera are climbers that can scramble through rainforest trees to <a href="https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b605#:%7E:text=Monstera%20deliciosa%2C%20commonly%20called%20split,is%20native%20to%20Central%20America">heights</a> of 25 metres or more. </p>
<p>Their large perforated leaves can be over a metre long, with regular nodes along the stem and roots often growing from these nodes. The roots help them hook onto other plants as they climb to access light. </p>
<p>There are about <a href="https://www.britannica.com/plant/Monstera">50 species</a> in the Monstera genus and some – such as <em>Monstera adansonii</em> (Adanson’s monstera or five holes plant) and <em>Monstera siltepecana</em> (silver monstera) – are popular indoor plants.</p>
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<a href="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519437/original/file-20230404-28-5ij9dr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Monstera adansonii is a popular indoor plant.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>The name Monstera dates back to the <a href="https://www.aroid.org/genera/monstera/Madison_Monstera_Rec.pdf">1700s</a>, but these days most people associate this part of the name with its massive leaves. They are, after all, real monsters.</p>
<p>These huge leaves develop wherever there is a patch of light and allow the plant to grow quickly and shade out nearby competition. </p>
<p>The species name, deliciosa, refers to its fruit, which <a href="https://plants.ces.ncsu.edu/plants/monstera-deliciosa/">tastes</a> a little like a cross between banana and pineapple. </p>
<p>Monsteras are related to the arum lilies and produce white flowers on a fleshy stem (known as a “spadix”) that is surrounded by a cream or white leaf-like structure or bract (known as a “<a href="https://www.gardeningknowhow.com/garden-how-to/info/what-is-a-spathe.htm">spathe</a>”).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519439/original/file-20230404-18-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The fruit can be eaten.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Our first and only monstera began its life with us as a rather small indoor plant given as a gift in 1980. It remained indoors for a year or two, growing well, but then proved too great a temptation for a curious young son.</p>
<p>It was moved in its container (which was, by then, larger than its original pot) into a protected corner of an outside patio. </p>
<p>It had done well indoors, growing in a good quality potting medium, getting plenty of sunlight and regular water. Its leaves had gone from small philodendron-like features into the large and perforated foliage of the Swiss cheese plant.</p>
<p>The move outdoors did it no harm. Good light, regular water, fresh air and protection from winds and frosts saw it flourish into a plant with many large leaves and measuring nearly two metres in height. It filled a corner beautifully.</p>
<h2>A forgiving plant</h2>
<p>Monsteras are quite forgiving indoor plants. They are quite hardy (like many climbers) but as a tropical plant they like warm, humid conditions and moist, well-drained soils. </p>
<p>They also tolerate shade and so it’s not surprising they do well <a href="https://plants.ces.ncsu.edu/plants/monstera-deliciosa/">indoors</a>. </p>
<p>If you have a humus-rich potting medium and provide a climbing frame for them, they can thrive and survive for many years inside. However, you may need to give them a liquid fertiliser every year or two and re-pot them into a larger container.</p>
<p>While they are hardy and relatively easy to cultivate, Monsteras can decline if they become waterlogged.</p>
<p>This can easily happen if you over-water plants and have the container on a dish that gathers water.</p>
<p>Direct sunlight near a window can burn their leaves or lead to scorched patches. Leaves can also be damaged by warm dry air if plants are placed too close to heaters or heating ducts.</p>
<p>Their large leaves may also need dusting as the surfaces can become quite dirty, especially in bathrooms. The occasional prune will prevent the plant becoming too big indoors and removes yellow, burnt and older leaves.</p>
<p>Like many indoor plants, monsteras can benefit from a bit of R-and-R outdoors in a warm, sheltered spot for a few days.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519442/original/file-20230405-28-3ws3in.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Yellow leaves are a sign you’re likely doing something wrong.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Easily propagated</h2>
<p>As a fashionable plant, large monsteras can be quite pricey and variegated forms which grow more slowly are even more <a href="https://theconversation.com/multi-coloured-plants-are-suddenly-a-home-decor-must-have-heres-how-to-keep-them-alive-181163">expensive</a>.</p>
<p>However, <em>Monstera deliciosa</em> can be readily propagated from cuttings.</p>
<p>The easiest and quickest way of getting a new plant is to take a section of stem with a leaf or two attached and, if possible, with a few developing roots. Place it in a good quality potting mix in a large container.</p>
<p>You can also aerial layer monsteras, which is where you wrap potting mix or sphagnum moss around a node, preferably with some roots, in plastic or cling wrap. Make a couple of slash-like cuts in the stem and when roots develop, take your cutting from the stem.</p>
<p>They grow and establish quickly. So quickly, in fact, they’re considered a <a href="https://keyserver.lucidcentral.org/weeds/data/media/Html/monstera_deliciosa.htm">weed</a> along some New South Wales rivers.</p>
<p>After being on the patio for several years, the patio was to be demolished for an extension and our monstera either had to go or be planted in the garden. </p>
<p>We chose the latter and planted it in what we thought was an appropriate spot. </p>
<p>The monster responded as only a successful rainforest climber could. It spread, it climbed, it fruited and wherever there was a patch of light, it oriented a giant Swiss cheese leaf to gain maximum benefit for photosynthesis. </p>
<p>It is now over 40 years old, many metres long as it meanders its way through the garden and has been the source of several successful cuttings for family and friends.</p>
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<em>
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Read more:
<a href="https://theconversation.com/trees-can-be-weeds-too-heres-why-thats-a-problem-182599">Trees can be weeds too – here's why that's a problem</a>
</strong>
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<img src="https://counter.theconversation.com/content/202851/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The large, iconic leaves of monstera can now be found everywhere in popular culture – from fabric prints and earrings to tattoos and mugs. What makes monstera special and how do you keep one healthy?Gregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2001402023-02-23T06:15:26Z2023-02-23T06:15:26ZSome houseplants take in nutrients from roots outside the soil – and it may change how we care for them<p>In recent years, we have seen growing interest in houseplants, particularly <a href="https://www.theguardian.com/lifeandstyle/2022/jan/16/how-youthful-plant-lovers-are-shaking-up-staid-old-horticultural-ways">among younger generations</a>. Between 2019 and 2022, houseplant sales in the UK <a href="https://gca.org.uk/garden-centres-saw-green-shoots-of-recovery-in-2021/">increased by more than 50%</a>. Indoor plants are associated with a range of <a href="https://theconversation.com/houseplants-dont-just-look-nice-they-can-also-give-your-mental-health-a-boost-186982">environmental and health benefits</a> including cleaner air, better mental health and clearer thinking.</p>
<p>If you’re a plant parent, you probably know that plants need food and water to grow and survive. You will also know that plants have roots for taking these resources in and leaves to absorb the light energy required for photosynthesis. This sounds simple, but many of us (including me) struggle to keep our plants healthy.</p>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/513999/original/file-20230307-18-3frmra.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.</em> </p>
<p><em><a href="https://theconversation.com/topics/plant-curious-137238?utm_source=TCUK&utm_medium=linkback&utm_campaign=PlantCurious2023&utm_content=InArticleTop">This article is part of a series, Plant Curious</a>, exploring scientific studies that challenge the way you view plantlife.</em></p>
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<p>Many common houseplants, especially those in the <a href="http://www.aroid.org/aroid/">aroid family</a> like the <a href="https://en.wikipedia.org/wiki/Monstera_deliciosa">monstera</a> (or the Swiss cheese plant) and <a href="https://en.wikipedia.org/wiki/Philodendron">philodendron</a> evolved in tough conditions. In their tropical or subtropical forest homes, these plants begin life on the ground but quickly climb the nearest tree to escape the dimly lit forest floor. They produce aerial roots that grow from stems above the ground and attach the plant to a tree’s trunk, allowing them to climb.</p>
<p>Knowing whether these roots take up nutrients or not will influence how we care for these plants. Currently, people tend to feed them in the soil with regular watering and plant food. So in a <a href="https://onlinelibrary.wiley.com/doi/10.1111/pce.14568">recent study</a>, my colleague and I compared aerial and soil-formed roots’ ability to take up nitrogen, an important plant food. </p>
<p>We expected the soil roots to better take up nitrogen because the soil is where the nutrients are – certainly in most houseplant potting mixes. Instead, we found that the aerial roots were far more efficient at taking up nitrogen than their soil counterparts.</p>
<h2>Reach for the sky</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A monstera plant growing up a neighbouring tree." src="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511134/original/file-20230220-16-3wb5pv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Monstera climb aerial roots to access lighter areas of the forest canopy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/monstera-plants-growing-heights-20-metres-788113741">Pomme Home/Shutterstock</a></span>
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<p>As they climb, aroids grow more leaves. To sustain this growth, the plant will require more nutrients and water. Trees and shrubs effectively meet their demands for food and water by adding new pipes called xylem and phloem to the stem or roots. </p>
<p>The xylem is a tissue that transports water and nutrients upward, from the roots to the leaves. The phloem carries sugars the opposite way.</p>
<p>But monstera and philodendron (and other aroids) are instead related to grasses, meaning they are unable to make new pipes to take up resources. Without help, they would run out of suck – like trying to suck a thick milkshake through a small straw – leaving them unable to feed their increasing leaf area. </p>
<p>Monsteras and philodendrons overcome this problem by growing roots from the new stems as they grow (effectively adding more straws). These new roots grow downwards towards the soil where, in theory, they will take up nutrients and water. </p>
<p>But until now, this theory has not been tested.</p>
<h2>Caring for your plants</h2>
<p>We grew three common houseplants, a <a href="https://www.rhs.org.uk/plants/59193/philodendron-scandens/details">philodendron</a>, an <a href="https://www.gardenersworld.com/plants/anthurium-andreanum/">anthurium</a> (flamingo flower) and an <a href="https://www.rhs.org.uk/plants/32104/epipremnum-pinnatum-aureum/details">epipremnum</a> (devil’s ivy) both in humid conditions where there was plenty of water in the atmosphere, and in conditions typical of an office building (around 45% humidity).</p>
<p>After a few months, we recorded how big the plants were and then measured exactly how much nitrogen was taken up by each type of root. </p>
<p>Nitrogen uptake is measured by using a label – a bit like feeding flowers food dye. Nitrogen is present in nature in two “sizes”, called <a href="https://en.wikipedia.org/wiki/Isotopes_of_nitrogen">stable isotopes</a>. The heavy one, nitrogen-15, is far less abundant in nature than the lighter nitrogen-14, so when we fed the roots a solution high in the heavy nitrogen, we were able to measure how much of it was taken up compared to the other nitrogen isotope already in the roots. </p>
<p>To compare soil roots with aerial roots, we then fed the heavy nitrogen solution to individual roots and measured the amount of heavy nitrogen that was taken up by each. </p>
<p>Houseplants with more moisture in the air grew bigger and lost less water from their leaves during photosynthesis. In some situations, it was clear the plants were taking up water from their leaves.</p>
<p>Aerial roots were also much better at taking up nitrogen than soil roots. In anthurium and epipremnum, aerial roots took in up to 35% more nitrogen than the soil roots. </p>
<figure class="align-center ">
<img alt="A woman standing on a ladder tending to her houseplants." src="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511136/original/file-20230220-28-7c4vw9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Epipremnum’s aerial roots took in more nitrogen than the soil roots.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/focused-african-american-woman-tending-epipremnum-2244583755">DimaBerlin/Shutterstock</a></span>
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</figure>
<p>We are now exploring how and why this happens in more detail, but this could be because intense competition between neighbouring trees and shrubs in the plants’ original forest habitat strip soil of its nutrients. Being able to catch nutrients from decomposing leaf litter as they run down stems can thus be an advantage. The soil roots of some tropical trees even grow <a href="https://www.science.org/doi/10.1126/science.235.4792.1062">up the trunks</a> of neighbouring trees.</p>
<p>This suggests that we could be caring for these houseplants all wrong. We tend to ignore their aerial roots when all we need to do is give these roots a good spray with a liquid fertiliser. This will run down the aerial roots towards the stems and into the soil, making sure the soil roots are not neglected entirely.</p>
<p>Houseplants, particularly aroids, are a feature of many of our homes. But to fully experience their benefits, these indoor plants must be healthy. This may involve changing how we look after them.</p><img src="https://counter.theconversation.com/content/200140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Rasmussen does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research finds that some common houseplants take in nutrients from outside the soil.Amanda Rasmussen, Assistant Professor, Faculty of Science, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1811632022-04-14T05:30:09Z2022-04-14T05:30:09ZMulti-coloured plants are suddenly a home decor ‘must-have’. Here’s how to keep them alive<figure><img src="https://images.theconversation.com/files/457621/original/file-20220412-46278-pqir8z.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5065%2C3785&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Fads and fashion have always influenced the plants we keep. And so it is with variegated plants, which have become <a href="https://thatplantylife.com/affordable-and-gorgeous-variegated-houseplants/">very popular</a> with indoor plant enthusiasts these days.</p>
<p>Variegated plants possess multiple colours – typically on their leaves, but in some cases on stems, flowers and fruit. Their patterns include stripes, dots, edges and patches. They’re usually green with either white or yellow, but can also feature red, pink, silver and other colours.</p>
<p>Variegated plants can divide opinion. I recall a great aunt telling me many years ago of her great fondness for the variegated Aspidistra elatior growing her garden. But I’ve also heard gardeners and garden designers dismiss variegated foliage because it didn’t fit with their design or colour themes.</p>
<p>Now, it seems indoor variegated plants are considered a “<a href="https://www.apartmenttherapy.com/variegated-plant-care-tips-36878935">must-have</a>” home decor accessory. But before you rush out and buy one, make sure you know how to keep it happy.</p>
<figure class="align-center ">
<img alt="woman puts handful of dirt into plant pot" src="https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&rect=14%2C22%2C4889%2C3235&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457618/original/file-20220412-9671-rkr9nz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Variegated plants come in an array of colours and patterns.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Understanding variegated plants</h2>
<p>Most plant species are entirely green but occasionally a variegated individual arises. Some catch the eye of a dedicated plant collector or nursery worker and become a popular variety.</p>
<p>Plant variegation can occur for several reasons.</p>
<p>In some plants, such as the flowers of tulips, it’s due to a <a href="https://www.britannica.com/story/tulip-mania-how-a-plant-virus-fueled-a-speculative-frenzy">viral infection</a>. The resulting streaks of different colours may be cursed or valued depending on the aesthetic effect.</p>
<p>Others plants, such as those in the genus <a href="https://www.rbgsyd.nsw.gov.au/Stories/2019/Coleus-back-in-the-name-game">coleus</a>, are naturally patterned. Groups of cells produce different colour combinations, causing leaves to grow with attractive markings.</p>
<p>Plant variegations can also arise from genetic mutation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-are-leaves-green-86160">Curious Kids: Why are leaves green?</a>
</strong>
</em>
</p>
<hr>
<p>When growing variegated plants, it’s important to understand how the various colours affect the way it functions.</p>
<p>The green part of plants contains chlorophyll, a pigment essential for photosynthesis. (Photosynthesis, of course, is the process by which the leaves convert sunlight into oxygen and carbohydrate that provides energy for plants to grow.) </p>
<p>In variegated plants, white parts of leaves do not contain chlorophyll and so do not photosynthesise. </p>
<p>Yellow parts of leaves can help send energy to the chlorophyll, but can’t perform photosynthesis on their own. The same goes for some red, orange and pink patches of tissue.</p>
<p>But all cells in the leaf – green or not – use the plant’s energy. That means variegated plants are less efficient energy producers than their all-green counterparts, which causes them to grow more slowly.</p>
<p>Some plants have mutated into <a href="https://www.chicagobotanic.org/blog/how_to/science_activity_albino_plants">albinos</a> containing no chlorophyll. These normally die within a few days or weeks of germination.</p>
<figure class="align-center ">
<img alt="two indoor variegated plants in pots" src="https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457623/original/file-20220412-36930-x4khyj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Yellow parts of leaves do not photosynthesise.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Caring for your plant indoors</h2>
<p>It’s no coincidence many popular indoor plants – such as coleus, philodendrons, monsteras, dracaenas and calatheas – are variegated. Because they’re usually far less vigorous than all-green versions of the species, they won’t be pushing against the ceiling within weeks. </p>
<p>The decorative colour and pattern of a variegated indoor plant is an added bonus.</p>
<p>Variegated plants can take longer than others to reach a size considered appropriate for sale at a nursery, so may be comparatively more expensive. But there are ways to protect your variegated investment.</p>
<p>First, watch out for “reversion”. This can occur when a variegated plant sends up an all-green shoot. The shoot will grow fast compared to the variegated parts and can eventually take over, causing the whole plant to revert to green. </p>
<p>To avoid this, vigilantly remove any green shoots before they get big.</p>
<p>You don’t want variegated plants quickly outgrowing their space, but remember they’re low on chlorophyll and so need good light.</p>
<p>And like any indoor plant, ensure its leaves are kept free of fine dust and you don’t give it too much, or too little, water.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-apartment-dwellers-need-indoor-plants-80196">Why apartment dwellers need indoor plants</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="plants on sun-drenched windowsill" src="https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457625/original/file-20220412-26-9divrh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Indoor variegated plants need good light to make up for the lack of chlorophyll.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Variegated plants in the garden</h2>
<p>The popularity of indoor variegated plants will almost certainly lead to greater use outdoors.</p>
<p>Their slow-growing nature means outdoor variegated plants are usually much less likely to be “weedy” and spread where they’re not wanted. </p>
<p>This can be an advantage if you’ve avoided planting a species because it will take over the garden. The variegated versions of <a href="https://www.plantmark.com.au/pittosporum-eugenioides-variegata">pittosporum</a>, ficus and <a href="https://www.rhs.org.uk/plants/57250/nerium-oleander-variegatum-(v)/details">nerium oleander</a>, for example, are far less intent on global domination than their all-green counterparts.</p>
<p>When planting a variegated plant outdoors, watch that it doesn’t become shaded by other quicker-growing plants. Many variegated plants already struggle to photosynthesise sufficiently. A bit of extra shade can damage or even kill them.</p>
<p>So ensure they get enough light – and every so often give them a hand by trimming back nearby plants.</p>
<figure class="align-center ">
<img alt="green and purple plants in garden" src="https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457629/original/file-20220412-23-r12327.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ensure variegated plants are not over-shaded.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Growing with flying colours</h2>
<p>Variegated plants are having their moment in the sun. But their interesting biology is always in fashion!</p>
<p>These plants can brighten up your indoor space and provide attractive colour and pattern in the garden.</p>
<p>By learning about how variegated plants function and considering their special requirements, you can enjoy them for years to come.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trees-get-sunburnt-too-but-there-are-easy-ways-to-protect-them-from-tree-sunscreen-to-hydration-172953">Trees get sunburnt too – but there are easy ways to protect them, from tree 'sunscreen' to hydration</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/181163/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Variegated plants can be more expensive than their all-green counterparts. But there are ways to protect your investment.Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1353202020-04-29T04:18:59Z2020-04-29T04:18:59ZCan’t go outside? Even seeing nature on a screen can improve your mood<figure><img src="https://images.theconversation.com/files/329648/original/file-20200422-13258-47yp4k.jpg?ixlib=rb-1.1.0&rect=89%2C29%2C3875%2C2942&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Damon Hall/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Are you feeling anxious or irritated during the coronavirus lockdown? Do you constantly want to get up and move? Maybe you need a moment to engage with nature. </p>
<p>Getting into the great outdoors is difficult at right now. But our research soon to be published in <em>Australian Forestry</em> shows you can improve your mood by experiencing nature indoors. This could mean placing few pot plants in the corner of your home office, or even just looking at photos of plants.</p>
<p>Our work adds to <a href="https://theconversation.com/biodiversity-and-our-brains-how-ecology-and-mental-health-go-together-in-our-cities-126760">a compelling body of research</a> that shows being around nature directly benefits our mental health. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329659/original/file-20200422-39191-p8qyxt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Virtual images of nature have similar effects to being in the physical presence of nature.</span>
<span class="attribution"><span class="source">Kishoor Nishanth/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Biophilia</h2>
<p>Public gardens and parks, street verges with trees and bushes, and even rooftop gardens bring us a <a href="https://www.tandfonline.com/doi/full/10.1080/10630732.2019.1637694">broad range of benefits</a> – boosting <a href="https://doi.org/10.1016/S0749-3797(00)00317-2">physical health</a>, reducing <a href="https://doi.org/10.1016/j.envpol.2013.12.011">air pollution</a>, and even <a href="https://doi.org/10.3390/bs4040394">lowering crime rates</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/biodiversity-and-our-brains-how-ecology-and-mental-health-go-together-in-our-cities-126760">Biodiversity and our brains: how ecology and mental health go together in our cities</a>
</strong>
</em>
</p>
<hr>
<p>But inside, in your hastily constructed home office or home school room, you may be unable to take full advantage of <a href="https://theconversation.com/green-for-wellbeing-science-tells-us-how-to-design-urban-spaces-that-heal-us-82437">urban nature</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329652/original/file-20200422-39184-9vi2ly.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Natural products such as wooden furniture can also improve working conditions.</span>
<span class="attribution"><span class="source">Noemi Macavei Katocz/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Embracing the notion of “biophilia” – the innate human affinity with nature – while locked down inside may improve your productivity and even your health. </p>
<p>The <a href="https://theconversation.com/building-a-second-nature-into-our-cities-wildness-art-and-biophilic-design-88642">biophilia hypothesis</a> argues modern day humans evolved from hundreds of generations of ancestors whose survival required them to study, understand and rely on nature. So a disconnection from nature today can cause <a href="https://link.springer.com/article/10.1023/A:1010043827986">significant issues for humans</a>, such as a decline in psychological health.</p>
<p>In practice at home, connecting with nature might mean having large windows overlooking the garden. You can also <a href="https://makeitwood.org/documents/doc-1624-pollinate-health-report---february-2018.pdf">improve working conditions</a> by having natural materials in your office or school room, such as wooden furniture, natural stones and pot plants. </p>
<h2>Indoor plants</h2>
<p>Our research has demonstrated that even a small number of plants hanging in pockets on along a busy corridor provide enough nature to influence our physiological and psychological perceptions. </p>
<p>These plants even caused behavioural differences, where people would <a href="https://www.sciencedirect.com/science/article/abs/pii/S1618866717306763">change their route</a> through a building to come into contact with the indoor plants.</p>
<p>We surveyed 104 people, and 40% of the respondents reported their mood and emotions improved in the presence of indoor plants.</p>
<p>They felt “relaxed and grounded” and “more interested”. The presence of indoor greenery provides a place to “relax from routine” and it made the space “significantly more pleasant to work in”. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329642/original/file-20200422-13228-1o7kkfx.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Our study showed the benefits of indoor greenery.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>As one person reported: </p>
<blockquote>
<p>When I first saw the plants up on the wall brought a smile to my face.</p>
<p>Whenever I walk down the stairs or walk past I mostly always feel compelled to look at the plants on the wall. Not with any anxiety or negative thoughts, rather, at how pleasant and what a great idea it is.</p>
</blockquote>
<h2>Looking at wildlife photography</h2>
<p>Our research also explored whether viewing images, posters or paintings of nature would make a difference.</p>
<p>We photographed the plants from viewpoints similar to those the corridor users experienced. Survey responses from those who only viewed these digital images were almost the same as those who experienced them in real life. </p>
<p>While we can’t say for sure, we can hypothesise that given the importance of vision in modern humans, an image that “looks” like nature might be enough to trigger a biophilic response. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-know-contact-with-nature-makes-you-feel-better-can-virtual-contact-do-the-same-111752">We know contact with nature makes you feel better. Can virtual contact do the same?</a>
</strong>
</em>
</p>
<hr>
<p>However, physically being in the presence of plants did have some stronger behavioural effects. For example corridor users wanted to linger longer looking at the plants than those who viewed the photographs, and were more likely to want to visit the plants again. Maybe the other senses - touch, smell, even sound - created a stronger biophilic response than just sight alone.</p>
<p>So the good news is if you can’t get to a nursery – or if you have a serious inability to keep plants alive – you can still benefit from looking at photographs of them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329650/original/file-20200422-39156-yuzyyv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Looking at photos of nature can improve your mood.</span>
<span class="attribution"><span class="source">Bee Balogun/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>If you haven’t been taking your own photos, search the plethora of images from wildlife photographers such as <a href="http://gimesy.com/">Doug Gimesy</a>, <a href="http://lanting.com/">Frans Lanting</a> and <a href="https://www.tanyastollznow.com/">Tanya Stollznow</a>. </p>
<p>Or check out live camera feeds of a wide range of environments, and travel to far-flung places without leaving the safety of home. </p>
<p>While we haven’t tested the mood-boosting effects of live videos, we hypothesise their physiological and psychological effects will be no different than digital photographs.</p>
<p>Here are seven places to help you get started.</p>
<ul>
<li><p>The <a href="https://bushblitz.org.au">Bush Blitz</a> citizen science app launched a new online tool today. The species recovery program encourages children to explore their backyard to identify different species. </p></li>
<li><p>“From the bottom of the sea direct to your screen”: watch this <a href="https://www.natureaustralia.org.au/what-we-do/our-priorities/oceans/ocean-stories/reef-cam-underwater/">underwater live stream</a> of Victoria’s rocky reef off Port Phillip Bay</p></li>
<li><p>The Coastal Watch website offers <a href="https://www.coastalwatch.com/surf-cams-surf-reports">live camera feeds on beaches</a> around Australia.</p></li>
<li><p>Watch the running water, trees and occasional fauna in California’s <a href="https://explore.org/livecams/zen-den/live-redwood-cam-1">Redwood Forest River</a>.</p></li>
<li><p>In pastoral Australia, go on a <a href="https://youtu.be/qqYFgqN_q-w">four-hour drive through the country side</a> along tree-lined roads. </p></li>
<li><p><a href="https://www.zoo.org.au/animal-house/">Zoos Victoria</a> has set up live cameras that show its animals in natural (and nature-like) environments from Melbourne Zoo and Werribee Open Range Zoo.</p></li>
<li><p>Yellowstone National Park may be closed right now, but <a href="https://www.nps.gov/yell/learn/photosmultimedia/webcams.htm?sf174893829=1">webcams are stationed</a> in various locations throughout the park.</p></li>
</ul>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-science-is-in-gardening-is-good-for-you-65251">The science is in: gardening is good for you</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/135320/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cris Brack has received funding from the Australian Research Council. He is a Member of the Institute of Foresters of Australia and the ACT Climate Change Council as well as a Senior Fellow of the Higher Education Academy.</span></em></p><p class="fine-print"><em><span>Aini Jasmin works as a tutor in Universiti Putra Malaysia. She has received funding from the Ministry of Higher Education Malaysia for her PhD. </span></em></p>Humans have an innate affinity with nature. Embracing this in your home while locked down may improve your productivity and health.Cris Brack, Associate Professor, Fenner School of Environment and Society, Australian National UniversityAini Jasmin Ghazalli, Graduate studentLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1200512019-07-22T10:58:27Z2019-07-22T10:58:27ZMicro-naps for plants: Flicking the lights on and off can save energy without hurting indoor agriculture harvests<figure><img src="https://images.theconversation.com/files/284584/original/file-20190717-147270-19g06yc.jpg?ixlib=rb-1.1.0&rect=328%2C194%2C4277%2C3113&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pulses of light followed by extended dark periods might help make indoor agricultural production more sustainable.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/led-lighting-used-grow-lettuce-inside-1384001177?studio=1">DutchScenery/Shutterstock.com</a></span></figcaption></figure><p>A nighttime arrival at Amsterdam’s Schiphol Airport flies you over the bright pink glow of vegetable production greenhouses. Growing crops under artificial light is <a href="https://www.marketwatch.com/press-release/at-396-cagr-vertical-farming-and-plant-factory-market-size-projected-to-cross-usd-11000-million-by-2024-2019-02-21">gaining momentum</a>, particularly in regions where produce prices can be high during seasons when sunlight is sparse.</p>
<p><a href="https://www.wur.nl/en/Dossiers/file/Vertical-farming.htm">The Netherlands</a> is just one country that has rapidly adopted <a href="https://en.wikipedia.org/wiki/Controlled-environment_agriculture">controlled-environment agriculture</a>, where high-value specialty crops like herbs, fancy lettuces and tomatoes are produced in year-round illuminated greenhouses. <a href="http://www.verticalfarm.com/?page_id=36">Advocates suggest</a> these completely enclosed buildings – or <a href="https://urbanagnews.com/blog/japan-special-report-plant-factories-with-artificial-light-pfal/">plant factories</a> – could be a way to repurpose urban space, decrease food miles and provide local produce to city dwellers.</p>
<p>One of the central problems of this process is the <a href="https://theconversation.com/food-security-vertical-farming-sounds-fantastic-until-you-consider-its-energy-use-102657">high monetary cost of providing artificial light</a>, usually via a combination of red and blue light-emitting diodes. <a href="https://doi.org/10.2183/pjab.89.447">Energy costs</a> sometimes exceed 25% of the operational outlay. How can growers, particularly in the developing world, <a href="https://www.voanews.com/usa/people-power-costs-keep-indoor-farming-down-earth">compete when the sun is free</a>? Higher energy use also translates to more carbon emissions, rather than the decreased carbon footprint sustainably farmed plants can provide.</p>
<p>I’ve <a href="https://scholar.google.com/citations?user=kIh3BRwAAAAJ&hl=en&oi=ao">studied how light affects plant growth and development</a> for over 30 years. I recently found myself wondering: Rather than growing plants under a repeating cycle of one day of light and one night of darkness, what if the same daylight was split into pulses lasting only hours, minutes or seconds?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284583/original/file-20190717-147295-16meq90.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Indoor plants need plenty of artificial light.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ventilator-special-led-lights-belts-above-1428413504?studio=1">josefkubes/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>Short bursts of light and dark</h2>
<p>So my colleagues and I <a href="https://doi.org/10.1016/j.envexpbot.2019.103803">designed an experiment</a>. We’d apply the normal amount of light in total, just break it up over different chunks of time.</p>
<p>Of course plants depend on light for photosynthesis, the process that in nature uses the sun’s energy to merge carbon dioxide and water into sugars that fuel plant metabolism. Light also directs growth and development through its signals about day and night, and monkeying with that information stream might have disastrous results.</p>
<p>That’s because breaking something good into smaller bits sometimes creates new problems. Imagine how happy you’d be to receive a US$100 bill – but not as thrilled with the equivalent 10,000 pennies. We suspected a plant’s internal clock wouldn’t accept the same luminous currency when broken into smaller denominations.</p>
<p>And that’s exactly what we <a href="https://doi.org/10.1016/j.envexpbot.2019.103803">demonstrated in our experiments</a>. Kale, turnip or beet seedlings exposed to cycles of 12 hours of light, 12 hours dark for four days grew normally, accumulating pigments and growing larger. When we decreased the frequency of light-dark cycles to 6 hours, 3 hours, 1 hour or 30 minutes, the plants revolted. We delivered the same amount of light, just applied in different-sized chunks, and the seedlings did not appreciate the treatment. </p>
<p>The same amount of light applied in shorter intervals over the day caused plants to grow more like they were in darkness. We suspect the light pulses conflicted with a <a href="https://doi.org/10.1105/tpc.106.040980">plant’s internal clock</a>, and the seedlings had no idea what time of day it was. Stems stretched taller in an attempt to find more light, and processes like pigment production were put on hold.</p>
<p>But when we applied light in much, much shorter bursts, something remarkable happened. Plants grown under five-second on/off cycles appeared to be almost identical to those grown under the normal light/dark period. It’s almost like the internal clock can’t get started properly when sunrise comes every five seconds, so the plants don’t seem to mind a day that is a few seconds long.</p>
<p>Just as we prepared to publish, undergraduate collaborator Paul Kusuma found that our discovery was not so novel. We soon realized we’d actually rediscovered something already known for 88 years. Scientists at the U.S. Department of Agriculture <a href="https://naldc.nal.usda.gov/download/IND43968018/PDF">saw this same phenomenon in 1931</a> when they grew plants under light pulses of various durations. Their work in mature plants matches what we observed in seedlings with remarkable similarity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/285200/original/file-20190722-11339-185bjd3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A 1931 study by Garner and Allard tracked the growth of Yellow Cosmos flowers under light pulses of various durations.</span>
<span class="attribution"><span class="source">J. Agri. Res. 42: National Agricultural Library, Agricultural Research Service, U.S. Department of Agriculture.</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Not only was all of this a retread of an old idea, but pulses of light do not save any energy. Five seconds on and off uses the same amount of energy as the lights being on for 12 hours; the lights are still on for half the day. </p>
<p>But what would happen if we extended the dark period? Five seconds on. Six seconds off. Or 10 seconds off. Or 20 seconds off. Maybe 80 seconds off? They didn’t try that in 1931.</p>
<h2>Building in extra downtime</h2>
<p>It turns out that the plants don’t mind a little downtime. After applying light for five seconds to activate photosynthesis and biological processes like pigment accumulation, we turned the light off for 10, or sometimes 20 seconds. Under these extended dark periods, the seedlings grew just as well as they had when the light and dark periods were equal. If this could be done on the scale of an indoor farm, it might translate to a significant energy savings, at least 30% and maybe more.</p>
<p>Recent yet-to-be published work in our lab has shown that the same concept works in leaf lettuces; they also don’t mind an extended dark time between pulses. In some cases, the lettuces are green instead of purple and have larger leaves. That means a grower can produce a diversity of products, and with higher marketable product weight, by turning the lights off.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=440&fit=crop&dpr=1 754w, https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=440&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/284079/original/file-20190715-173342-1fvujyt.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=440&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One variety of lettuce grew purple when given a 10-second dark period. They look similar to those grown with a five-second dark period, yet use 33% less energy. Extending the dark period to 20 seconds yielded green plants with more biomass.</span>
<span class="attribution"><span class="source">J. Feng, K. Folta</span></span>
</figcaption>
</figure>
<p>Learning that plants can be grown under bursts of light rather than continuous illumination provides a way to potentially trim the expensive energy budget of indoor agriculture. More fresh vegetables could be grown with less energy, making the process more sustainable. My colleagues and I think this innovation could ultimately help drive new business and feed more people – and do so with less environmental impact.</p>
<hr>
<p><em>This article was updated with a corrected legend on the photograph of the plants grown in 1931.</em></p><img src="https://counter.theconversation.com/content/120051/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin M. Folta received funding from the United States Department of Agriculture National Institute of Food and Agriculture and Vindara Inc to work on questions in agricultural lighting. He is affiliated with Eggsotics Eggs and Produce where his family grows some direct-market produce under hydroponic and/or artificial light conditions. He is reimbursed for travel related to talks in research and science communication. A full list of prior research funding may be seen at <a href="http://www.kevinfolta.com/transparency">www.kevinfolta.com/transparency</a></span></em></p>Indoor plant factories have high energy costs since LEDs replace the sunlight outdoor plants get for free. Scientists found a way to dial back how much light is needed by breaking it into tiny bursts.Kevin M. Folta, Professor of Horticultural Sciences and Plant Molecular and Cellular Biology, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/877582018-01-07T19:08:46Z2018-01-07T19:08:46ZHeading back to the office? Bring these plants with you to fight formaldehyde (and other nasties)<p>Humans have built high-rises since ancient Roman times, but it wasn’t until the 20th century that they became the default work space for a significant slice of the world’s workers. While these buildings are certainly efficient, they can cause <a href="https://link.springer.com/article/10.1007/s10654-013-9809-8">real health issues</a>. </p>
<p>Office buildings, where many Australians spend much of their time, are even worse than apartment buildings. Cubicles in offices <a href="http://www.sciencedirect.com/science/article/pii/S0360132309003199">usually consist</a> of partitions made of particle board and vinyl carpet, synthetic flooring, a particle board desk and plastic or synthetic office chair, mostly lit by artificial lighting. The lucky few get natural light and a view from a window, but <a href="https://www.hindawi.com/journals/apm/2011/124064/abs">poor ventilation still spreads germs</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-apartment-dwellers-need-indoor-plants-80196">Why apartment dwellers need indoor plants</a>
</strong>
</em>
</p>
<hr>
<p>One excellent way to combat both sick days and stress is by filling your office with plants. Ideally, you want plants that will “scrub” the air of pathogens, improve the office’s mix of bacteria, and survive in low light with little care. </p>
<h2>Fight formaldehyde (and other nasty chemicals)</h2>
<p>One of the many chemical compounds given off by synthetic office furnishings is <a href="https://theconversation.com/clearing-the-air-the-hidden-wonders-of-indoor-plants-15339">formaldehyde</a>, which can irritate the mucous membranes of the eyes, nose and throat, and also cause allergic contact dermatitis. </p>
<p>Irritation of the eyes and upper respiratory tract, as well as headaches, are the most common reported symptoms of <a href="http://www.wolvertonenvironmental.com/NASA-Report-89.pdf">exposure to formaldehyde toxins</a>. Other harmful chemicals in the office may include benzene, ethylbenzene, toluene and xylene, and even ammonia from cleaning products. High levels of carbon dioxide breathed out by a roomful of colleagues can give the room that “stuffy” feeling, particularly if there is no air conditioning.</p>
<p>Indoor plants will purify the air, reducing <a href="https://theconversation.com/why-apartment-dwellers-need-indoor-plants-80196">volatile organic compounds</a>, including formaldehyde.</p>
<p>A NASA <a href="https://archive.org/details/nasa_techdoc_19930072988">clean air study</a> tested common indoor plants for the ability to filter pollutants, and found many are very effective at removing multiple kinds of organic compounds from the air (<a href="https://en.wikipedia.org/wiki/NASA_Clean_Air_Study">this chart</a> is very handy for finding high performers). </p>
<p>To best remove indoor pollutants, try for <a href="https://pursuit.unimelb.edu.au/articles/how-a-pot-plant-or-five-is-good-for-you?ct=t(UniMelb_Experts_Wednesday_September_6_209_5_2017)">one medium-sized plant per 2.2 square metres</a>. Look for species with large leaves (the more leaf surface area, the more efficient it is). </p>
<h2>Improve indoor bacteria balance</h2>
<p>There are already trillions of bacteria in high-rise offices, but only a limited amount come in through open windows and air conditioning from the outdoor environment. Most of the bacteria, fungi and viruses come from people; we leave behind a <a href="https://peerj.com/articles/1258/">microbial cloud</a> from our skin wherever we go. </p>
<p>The office environment then creates new habitats for microbial communities that may be quite foreign to human skin, and may not be good for your health.</p>
<p>Beneficial bacteria on indoor plants and in their soil are an important addition to the office, stabilising the ecology of the built synthetic environment. </p>
<p>Plant-associated bacteria could also help to avoid outbreaks of pathogens by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905206/">enhancing microbial biodiversity</a> and balancing the complex network of the ecosystem. A wholesome balance may reduce the incidence of viral illness and the number of sick days among staff.</p>
<p>It’s not just the size of the plant that’s important here. Larger pots mean more root mass and soil surface for helpful bacteria and root microbes. </p>
<h2>Beat stress</h2>
<p>Over the past 30 years, research has shown that green spaces promote public health, and that contact with nature can shift highly stressed people to a <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(06)69921-2/abstract">more positive emotional state</a>. One <a href="http://www.sciencedirect.com/science/article/pii/S016920460900231X">study</a> identified eight ways people perceive green urban spaces (described as Serene, Space, Nature, Rich in Species, Refuge, Culture, Prospect, and Social) and confirmed the importance of considering plant life when creating public places. </p>
<p>Offices, particularly those with many people, poor ventilation or low natural light, should also consider plants and green spaces a necessity. </p>
<p>There are a few basic principles for a good office plant. It must be hardy and easy to maintain, and able to survive without water over weekends (or when the regular plant-carer goes on holiday). Many plants will do the most good in cubicles and spaces away from windows, so they need to be adapted to low light.</p>
<p>It’s also a good idea to avoid plants that flower extravagantly, which may cause allergic reactions. Check with your colleagues before introducing new plants.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hay-fever-survival-guide-why-you-have-it-and-how-to-treat-it-34000">Hay fever survival guide: why you have it and how to treat it</a>
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<p>Some of the best all-rounders across these categories are Devil’s Ivy, Bamboo Palm, Kentia Palm, Variegated Snake Plant (also known as mother-in-law’s tongue), and the Peace Lily, but there are many beautiful plants that will improve your atmosphere and mood. </p>
<p>So if you’re heading back to work in an office soon (or know someone who is), why not bring along an indoor plant?</p><img src="https://counter.theconversation.com/content/87758/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Most modern offices contain a surprising amount of harsh chemicals. If you’re heading back to work, check out our list of the best plants to clean the air (and reduce stress).Danica-Lea Larcombe, PhD Candidate in Biodiversity and Human Health, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/800772017-08-31T23:27:02Z2017-08-31T23:27:02ZNot just nice to have: nature in the workplace makes employees happier and healthier<figure><img src="https://images.theconversation.com/files/184124/original/file-20170831-25683-13bd22p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Just seeing plants can have a huge impact on your mood.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Bringing nature into the workplace can help reduce stress and increase creativity and focus, research shows. </p>
<p>Some researchers suggest humans have an innate need to be connected with nature. This is called <a href="https://www.britannica.com/science/biophilia-hypothesis">biophilia</a>. But as housing density, <a href="https://theconversation.com/get-used-to-your-commute-data-confirms-houses-near-jobs-are-too-expensive-77867">commute times</a>, and office hours increase, we are spending less and less time in natural environments. </p>
<p>Workplace stress costs American businesses <a href="http://pubsonline.informs.org/doi/pdf/10.1287/mnsc.2014.2115">up to</a> US$190 billion every year in healthcare costs alone. This is why bringing nature into the office can have such a big impact on employee wellbeing. </p>
<p>Incorporating nature into the workplace can take many different forms including living green walls, indoor trees and planter boxes. Even views of nature on television screens or art can positively impact mood and wellbeing.</p>
<h2>Your environment has a huge impact on mood</h2>
<p>Just being able to see nature has been shown to increase <a href="http://pubs.acs.org/doi/abs/10.1021/es903183r">both self-esteem and mood</a>, particularly among younger people. </p>
<p><a href="http://www.sciencedirect.com/science/article/pii/0272494495900012">Attention restoration theory</a> suggests that looking at nature can cause the brain to shift into a different mode of processing. <a href="http://www.sciencedirect.com/science/article/pii/S0272494415000328">Researchers</a> studied brain scans of people who were randomly assigned to look at pictures of a green meadow or a concrete roof for 40 seconds. Even this brief glimpse of nature <a href="http://www.sciencedirect.com/science/article/pii/S0272494415000328">was enough</a> to shift the brain into a more relaxed mode. </p>
<p>Researchers also got the participants to do a task that measured their attention. The ones who had seen the picture of the meadow performed significantly better than the others, making less mistakes and getting less distracted. </p>
<p>Several other <a href="https://link.springer.com/article/10.1007/s12199-009-0091-z">experiments</a> and <a href="http://cvcl.mit.edu/SUNSeminar/biederman_vessel_amsci06.pdf">studies</a> that included sounds of running water and forest smells also <a href="http://www.sciencedirect.com/science/article/pii/S0272494405801847">show</a> that exposure to nature not only improved subjective measures of stress, but also physiological factors like heart rates and blood pressure.</p>
<h2>Nature and the workplace</h2>
<p><a href="http://www.d-science.nl/wp-content/uploads/sites/2/2015/10/OR10_Daylighting-Bias-and-Biophilia.pdf">Researchers in America</a> looked at the connection between environment and employee sickness. They found that 10% of employee absences could be explained by office design that did not include views of nature or sufficient daylight. </p>
<p>Another <a href="http://psycnet.apa.org/record/2014-30837-001">study</a> from the United Kingdom found that bringing plants into workplace not only increased productivity by 15%, but also increased concentration and workplace satisfaction.</p>
<p>But even where there aren’t windows onto nature, and it isn’t possible to bring in plants, some of the same effects can be achieved. Simulated views of nature, using high definition televisions, have also been <a href="http://pubs.acs.org/doi/full/10.1021/es305019p">shown</a> to create positive effects, such as lowering heart rates and blood pressure. </p>
<p>But it’s not just the sights and sounds of nature that are beneficial. It’s also good to create <a href="https://www.terrapinbrightgreen.com/reports/14-patterns/#refuge">spaces</a> where employees can go to take time out, such as indoor gardens. These spaces provide opportunities for restoration, privacy and retreat from noise.</p>
<p>The importance of well designed spaces such as these for employees appears particularly relevant with the rise of open-plan workplaces where employees may have little <a href="http://www.sciencedirect.com/science/article/pii/S0272494413000340">respite</a> from noise and distraction. </p>
<p>When I started my working life, the only plants in the office were the occasional dusty, limp palm. In recent years, it seems as if every new office, cafe and public building has a green wall. The research shows this is not just another office design fad. There is a business case for bringing nature into the office, in terms of reduced costs and increased employee wellbeing and happiness.</p><img src="https://counter.theconversation.com/content/80077/count.gif" alt="The Conversation" width="1" height="1" />
Bringing nature into the workplace can lead to a number of benefits, including reduced stress and increased creativity.Libby (Elizabeth) Sander, Lecturer, Bond Business School, Bond UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/801962017-07-24T02:00:58Z2017-07-24T02:00:58ZWhy apartment dwellers need indoor plants<figure><img src="https://images.theconversation.com/files/178203/original/file-20170714-14258-zmw495.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The health benefits of being close to nature are well established.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/xXk6ASFrOus">priscilla du preez/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The number of Australians living in high-rise apartments <a href="http://www.abs.gov.au/AUSSTATS/abs@.nsf/Lookup/4102.0Main+Features30April+2013">doubled between 1991 and 2011</a> and that trend has continued since then. The quarter-acre dream is fast disappearing and larger blocks and family gardens along with it. As more people move from country areas to the city and as land to build homes near the city centre becomes scarce, we’re getting further and further away from nature. It turns out this isn’t great for our health.</p>
<p>The change in urban environments because of development, associated with a rapid increase in chronic disease, is a global phenomenon in developed countries. In the past children grew up running on bare soil and grass, explored backyard farms and gardens, climbed trees and were <a href="http://onlinelibrary.wiley.com/doi/10.1111/all.12545/full">exposed to a high level of bacteria</a>. And the <a href="https://academic.oup.com/mmy/article/53/7/717/959812">diversity of the bacteria</a> can change if an individual is exposed to different environmental conditions.</p>
<p>One of these conditions is living in a high-rise apartment far away from land, soil, trees and plants. Being close to nature is linked to positive mental well-being – and people living in urban areas have been <a href="http://willsull.net/resources/BratmanHamiltonDaily2012.pdf">shown to have a disadvantage</a> in processing stress. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428861/">This can be at least partially attributed</a> to increased exposure to air pollution and heat stress, and decrease in exercise and fitness through lack of access to a garden or nearby park. </p>
<p>The less exposure to nature we have, the less diverse the bacteria in our microbiota. The microbiota is the community of bacteria, fungi and viruses that live in our gut and on our skin. We need a diverse exposure for our body to <a href="http://www.int-res.com/articles/esep2014/14/e014p019.pdf">fight inflammation effectively</a>.</p>
<p>Alteration in the human bacterial communities, including the disappearance of ancient microbiotic species, is <a href="https://www.ncbi.nlm.nih.gov/pubmed/25904094">thought to cause inflammation in the body</a>. These ancient species were known to encourage development of cells that regulate the immune system (T-cells). When our immune system stays on high alert all the time, instead of resting when no threats are present, this causes inflammation, which can lead to chronic disease. </p>
<h2>Where plants come in</h2>
<p>The bacteria we have are similar to those of plants in that we both carry trillions of good and bad bacteria. The diversity of the microbiota is measured by how many families of bacteria are present. We know the diverse plant microbiome influences plant growth, and humans benefit by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166366/">eating plant foods</a>. An important research question remains: do we gain another benefit simply by having contact with plants? </p>
<p>Plants also remove volatile compounds from the air including ozone and carbon dioxide. They turn the carbon dioxide into oxygen, meaning <a href="https://link.springer.com/article/10.1007%2Fs11270-006-9124-z?LI=true">air quality is drastically improved</a>. Higher oxygen levels inside a small apartment mean well-being may be improved for the occupants. Viewing plants <a href="https://www.researchgate.net/profile/Roger_Ulrich4/publication/254315158_Visual_Landscapes_and_Psychological_Well-Being/links/0c96053a3fe7796728000000/Visual-Landscapes-and-Psychological-Well-Being.pdf">reduces stress and is pleasing</a> to the human eye.</p>
<p><a href="http://europepmc.org/abstract/med/21996763">Nature therapy</a> (shinrin-yoku), first invented in Japan, has proven beneficial for our health by lowering blood pressure and boosting mental health. This is done by simply going for a mindful walk in the forest.</p>
<p>It has also been <a href="http://www.sciencedirect.com.ezproxy.ecu.edu.au/science/article/pii/S0033350610003203">established</a> that plants confer positive changes in the brain’s electrical activity, muscle tension and heart activity.</p>
<h2>Some plants that are beneficial in the home</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178198/original/file-20170714-14254-a5x71r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Peace Lily.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/h_is_for_home/34687522722/in/photolist-URdC1A-5kXKYB-2in2DA-joTNrA-9cvTqW-9yJPsh-my9H4j-WfcVG3-aeVyM4-DLhTyT-hEQ2js-8qcL2e-VUATqw-xUoktE-5c9WWA-83zxqq-jAL9P3-4c6HwN-rAUGWp-3ToWZP-btCeBJ-5x5j3T-F3jgC-6Pd25Z-8hAnBy-6PhdB5-6Phbkm-54vKL6-rb2uwZ-56Zd5J-9P3onQ-83HJjx-ffsJJF-7vLQQT-feakCH-b6fJci-6okJuc-H4FmhW-b6fHWZ-56V3c2-oJihz4-qeirb5-bKB8YB-2hKUdA-a5Z5Af-6Yra1k-5yo2Pp-HF4ATW-bDJRp-dZrgh">H is for Hom/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Peace Lily: if this plant is placed in the hallway it will reduce many toxins such as <a href="http://www.sciencedirect.com/science/article/pii/S0045653514012508">benzene, ammonia, acetone and ethyl</a> and will prevent toxins from spreading between rooms in the apartment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178204/original/file-20170714-14248-mvhrf6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mother-in-law’s tongue.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/search/indoor-plants?photo=B6aJYT5wxkk">Mark Solarski/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p><em>Aloe vera</em> and Mother-in-Law’s Tongue: these plants placed in the bedroom <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC426300/">emit oxygen</a>, which <a href="http://www.sciencedirect.com/science/article/pii/S0034568798000681">improves sleep quality</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178200/original/file-20170714-14242-zesyii.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gerbera daisies.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/97477873@N00/14078422874/in/photolist-ns4ACS-9SLtVB-nawNAU-ns4B5y-4Z29J8-4Sf1eE-mJhygy-iuzQg-nrJYq5-4sw6Yb-9xUeP5-9Avsy6-aCKTcK-6qTGgU-cPifu9-5fwwAi-JBDF4q-mhS98k-5fBb7Y-RoTqK-wfJ5Yw-5fAVKs-7YnU9Y-b2QqAz-9GuBFb-dN4hvG-68YYBB-cPif9j-7NLWTZ-5fATGs-5fAU4Y-7ZuEY8-8wAYK2-ntHTNW-dYMEWY-7c68iG-9SiiFA-eUbBsb-4NDTZ1-rbVteW-xq2mb-4DiTUh-4ThLXt-zfJ4L-buaZ35-zgtUW-72zCTN-boTvNJ-ae55Rf-5oXJKA">Marcia O'Connor/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Gerbera daisy: if placed in the laundry these plants <a href="https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930073077.pdf">remove formaldehyde and benzene from the air</a>, which are in common household detergents.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=515&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=515&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178201/original/file-20170714-14287-14n8mn1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=515&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Devil’s Ivy.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dianesdigitals/8484334898/">DianesDigitals/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Devil’s Ivy (Golden Pothos): this plant can be placed in low light and cool temperatures such as an air-conditioned office or an outdoor garage. It will <a href="https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930073077.pdf">remove ozone</a>, which is found in car exhaust fumes.</p>
<h2>How about plants outside apartment buildings?</h2>
<p>Outdoor plants such as trees and shrubs help to shade our buildings and streets, cooling our concrete jungles. They also help with <a href="https://link.springer.com/chapter/10.1007/978-1-4615-4191-2_2">water runoff</a>, preventing flooding and <a href="https://pdfs.semanticscholar.org/dc4e/72771ff19d4e99de90c92e364836f431d9ab.pdf">nutrient dispersal</a>. <a href="http://www.uq.edu.au/economics/abstract/563.pdf">Suburbs with more canopy cover</a> have a perceived higher quality of living and attract better property prices.</p>
<p>Outdoor plants and soil have an abundance of ecological communities compared to indoor environments, a higher diversity of microbes, and therefore increase the numbers of insects, birds and other fauna. Viewing and being among large parks and green areas <a href="http://www.sciencedirect.com/science/article/pii/0169204686900058">has been shown to improve</a> the mental and physical well-being of people living in urban areas. </p>
<p>With <a href="http://www.news.com.au/finance/economy/australian-economy/country-towns-will-start-to-empty-out-with-the-rise-of-australias-supercities/news-story/98071fe8e5c18d6c5c807d45a8964683">backyards becoming increasingly rare</a>, diversity is decreasing in urban areas. In response, the City of Toronto has written into local law that all new buildings must have green roofs that include vegetation, drainage, waterproofing and slope stability. The <a href="https://www1.toronto.ca/wps/portal/contentonly?vgnextoid=678ad2e112f5c510VgnVCM10000071d60f89RCRD">reasoning for the law</a> was that green roofs provide:</p>
<blockquote>
<p>energy savings from better solar reflectivity, evapotranspiration and insulation, green roofs last up to twice as long as regular roofs, and green roofs can beautify and add value to Toronto’s buildings by providing scenic views and recreational areas in dense urban areas.</p>
</blockquote>
<p>A similarly bold strategy here would benefit not only the health of our apartment dwellers, but also the environment.</p><img src="https://counter.theconversation.com/content/80196/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pierre Horwitz is affiliated with the International Association for Ecology & Health. </span></em></p><p class="fine-print"><em><span>Danica-Lea Larcombe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Health benefits of being close to nature are well established, but the rise of apartment living means we can’t always be close to greenery.Danica-Lea Larcombe, PhD Candidate in Biodiversity and Human Health, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/591142016-05-10T12:40:45Z2016-05-10T12:40:45ZThe world health body you’ve never heard of – but should have<figure><img src="https://images.theconversation.com/files/121732/original/image-20160509-20605-10eg7gc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You are what you eat.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-404655226/stock-photo--an-agricultural-field-with-yellowed-ripe-cereal-in-the-summer.html?src=DZXFJB8yzTh-ILNxzBJ32g-1-90">www.shutterstock.com/rsooll</a></span></figcaption></figure><p>In a world where physical goods and living things are moved around with increasing frequency to more places, the opportunities for diseases and pests to spread are <a href="https://www.gov.uk/government/collections/detection-and-identification-of-infectious-diseases">multiplying all the time</a>. The consequences of new incursions can be catastrophic, hence the need for a trio of organisations that oversee health matters at a global level.</p>
<p>The World Health Organisation (WHO) is the best known of the triumvirate, most recently for the wrong reasons, because of <a href="http://www.scidev.net/global/ebola/news/Who-ebola-disease-failure-politicians.htm">fatal failures in responding to Ebola virus in West Africa</a>. The <a href="http://www.oie.int/">World Organisation for Animal Health</a> (OIE) is probably less familiar to many, though their importance has risen greatly over the last few decades because of the <a href="http://journalistsresource.org/studies/society/public-health/global-rise-human-infectious-disease-outbreaks">dramatic rise in the importance of zoonoses</a> – diseases that can be transferred from animals to humans.</p>
<p>The <a href="http://www.nhs.uk/Conditions/zika-virus/Pages/Introduction.aspx">Zika virus</a> is the latest disease to emphasise the close link between human and animal health, though it has been around since 1947, when it was <a href="http://www.cdc.gov/zika/about/">first discovered in Uganda</a>. Other zoonoses will doubtless appear, reinforcing the need for close cooperation between scientists and health professionals in combating joint threats to people and animals. The <a href="http://www.onehealthinitiative.com/">One Health movement</a> – which aims to unite human and veterinary medicine – began for this very reason, later spawning other initiatives such as <a href="https://ecohealth.net/en/">EcoHealth</a>.</p>
<p>So what about plants? The <a href="https://www.ippc.int/en/">International Plant Protection Convention</a> (IPPC) is the notional global body responsible for plant health. But its strapline of “protecting the word’s plant resources from pests” doesn’t exactly fire the imagination and create a vision of tackling fundamental threats to all living things. This is in essence what the IPPC is there to do, however – without plants there would be no people or animals.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/121886/original/image-20160510-20746-twn2yc.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Plant health is the basis of a healthy human population.</span>
<span class="attribution"><span class="source">Eric Boa</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The IPPC recently begun to smarten itself up with a livelier profile. The rather dull-sounding recent Eleventh Session of the Commission of Phytosanitary Measures <a href="https://www.ippc.int/en/news/the-ippc-theme-for-2016-plant-health-and-food-security/">led to the announcement</a> of the theme for 2016: plant health and food security. Of course all plant scientists these days claim, a little improbably, that their work is linked to “food security”, but it is good to see the IPPC expressing ambition.</p>
<p>The IPPC faces unusual challenges in raising its profile and becoming a more dominant player in protecting the world’s plant resources. Overseen and housed within the Food and Agricultural Organisation of the UN, it lacks a separate, independent status, and is more geared towards phytosanitary (plant health) regulation related to trade than the wider realm of agriculture. Soil fertility is, arguably, the most important determinant of plant health, yet global remits to ensure crops have enough to eat, so to speak, are split between other public bodies and organisations.</p>
<p>The WHO and OIE also have ambitious goals and there are <a href="https://www.researchgate.net/publication/268192151_Better_together_identifying_the_benefits_of_a_closer_integration_between_plant_health_agriculture_and_one_health">good reasons to align all three</a> global health bodies and foster collaborations, yet progress so far has been limited. The <a href="http://www.onehealthinitiative.com/">One Health movement</a> seems either <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10142562&fileId=S0031182015001845">uninterested or simply unaware</a> of plant health.</p>
<p>Efforts to promote better nutrition within the <a href="http://www.theguardian.com/global-development-professionals-network/2014/jan/22/agriculture-nutrition-improving-policy">wider context of agriculture</a> are an encouraging start to meaningful integration of human, animal and plant health. And concerns about pesticides and herbicides illustrate the clear connections between all three health sectors, as seen through the <a href="http://www.efsa.europa.eu/en/efsajournal/pub/4302">vigorous discussions</a> about the <a href="http://www.nature.com/news/widely-used-herbicide-linked-to-cancer-1.17181">carcinogenic properties of glyphosate</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/121890/original/image-20160510-20703-wtuegx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Healthy plants mean healthy people.</span>
<span class="attribution"><span class="source">Eric Boa</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>However, the IPPC’s focus on pests and diseases illustrates the difficulty of presenting a unified front for plant health (in its broadest sense). People have the WHO, animals have the OIE, and plants? Well, they have FAO, IPPC, the European food safety authority and a host of other organisations around the world who all play a part in regulating and maintaining plant health. It is one thing to talk about cross-sectoral collaborations and another to set them in motion.</p>
<p>Small changes have occured organically, however. Take, for example, the initiative of a food crop specialist in West Africa who showed <a href="http://agroinsight.com/downloads/books/Book-of-Video-stories-ALL.pdf">farmers videos</a> on growing crops alongside videos on cholera and tuberculosis because these “are of interest to people”. Videos like this are now used in six African countries to share farming ideas quickly.</p>
<p>And it is not such a big leap to imagine running health services in parallel. The Ebola virus exposed the <a href="https://theconversation.com/ebola-crisis-in-west-africa-where-did-all-the-development-money-go-31544">rotten state of primary healthcare</a> in West Africa, which donors and governments are <a href="http://www.heraldscotland.com/news/13952410.Restoration_of_Sierra_Leone_s_healthcare_system_begins_after_Ebola_outbreak_ends/?ref=rss">attempting to repair</a>. Why not seize the opportunity to integrate with an existing <a href="http://www.plantwise.org/plant-clinics/plant-clinic-locations/sierra-leone/">plant health programme in Sierra Leone</a>, for example?</p>
<p>Meanwhile, <a href="http://www.european-times.com/sector/government/dr-agnes-binagwaho-rwandas-minister-of-health/">dynamic countries such as Rwanda</a> are forging their own way ahead in cross-sectoral health collaborations, having <a href="http://www.rbc.gov.rw/IMG/pdf/one_health.pdf">officially adopted the One Health approach</a>, and offering new opportunities to look at health holistically.</p>
<p>The world’s least well-known health body, the IPPC, is part of the solution for raising and maintaining the well-being of people, though you would be hard pushed to recognise this currently. Restoring lives and livelihoods will also depend on <a href="http://www.accessagriculture.org/">healthy crop production</a> and <a href="https://www.plantvillage.org/">good advice</a> that encourages a closer alignment between primary human and plant healthcare. Healthy plants means healthier people.</p><img src="https://counter.theconversation.com/content/59114/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eric Boa has received funding from the Department for International Development and other international donors provided to CABI for plant clinics and related activities in Africa, Asia and Latin America.</span></em></p>The world looks to the WHO for all health-related matters – but it is only part of the picture.Eric Boa, Research fellow, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/153392013-07-09T20:37:35Z2013-07-09T20:37:35ZClearing the air: the hidden wonders of indoor plants<figure><img src="https://images.theconversation.com/files/26369/original/5rxb5g3v-1372384173.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Plants located in your home or office are beneficial to your health in more ways than you might think.</span> <span class="attribution"><span class="source">Miss Monk</span></span></figcaption></figure><p>It may come as a surprise but air pollution levels indoors are almost always higher than outside, even in busy city centres. Even more surprising is that indoor plants have the ability to mitigate high levels of most airborne contaminants.</p>
<p>Ventilation systems constantly “refresh” buildings with air from outdoors after a filtration process that removes some large particles, such as pollen, from it. Once inside, this air is augmented by a large range of indoor-sourced pollutants. </p>
<p>Two of the most significant of these are volatile organic compounds (VOCs) and carbon dioxide. </p>
<p>Volatile organic compounds are petrochemical vapours that are “outgassed” or continuously liberated from building materials, such as paint and carpet, as well as furnishings, plastics and electronic equipment. In high concentrations, many of these agents are acutely toxic and carcinogenic. Some even disrupt the endocrine systems of animals. </p>
<p>Up to 900 different compounds have been detected in some buildings. The most commonly found ones include benzene, ethylbenzene, toluene and xylene. </p>
<p>While the concentration of volatile organic compounds in modern buildings is generally quite low, there’s growing evidence that continued chronic exposure to even low levels of these chemicals may result in the condition known as <a href="http://www.ncbi.nlm.nih.gov/pubmed/19532093">sick building syndrome</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/26413/original/8k89rh3b-1372396659.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Indoor plants help break down hundreds of volatile organic compounds found in modern buildings.</span>
<span class="attribution"><span class="source">bfishadow</span></span>
</figcaption>
</figure>
<p>Sufferers of this syndrome experience acute or sub-acute discomfort and health effects that appear to be linked to the duration of time spent in a building. Typical symptoms range from drowsiness, physical irritability, difficulty concentrating, fatigue and nausea. </p>
<p>These symptoms can be severe enough to greatly diminish a person’s ability to work effectively. Their direct cause is usually unknown to the sufferer, but they’re relieved soon after leaving the building.</p>
<p>The other major indoor pollutant, carbon dioxide (CO<sub>2</sub>), is produced by human respiration. High levels of CO<sub>2</sub> (above 800 to 1,000 parts per million) cause rooms to feel “stuffy”. But sick building syndrome-like symptoms can occur at much lower concentrations than this. </p>
<p>When CO<sub>2</sub> levels are above 1,000 ppm, building occupants can become quite unwell. But this level is uncommon in modern buildings thanks to efficient mechanical ventilation systems.</p>
<h2>Natural air cleaners</h2>
<p>The ability of plants to improve indoor air quality was recognised in the 1980s, when NASA researched growing plants on space stations. <a href="http://archive.org/details/nasa_techdoc_19930072988">Results indicated</a> the surprising removal of previously high volatile organic compound concentrations in their model spacecraft. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/26415/original/7rz39q8h-1372396812.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">NASA pioneered research on plants and their ability to improve indoor air quality.</span>
<span class="attribution"><span class="source">NASA's Marshall Space Flight Centre</span></span>
</figcaption>
</figure>
<p>Initial research focused on the plant species themselves. But the consistency of the air-cleaning capacity among distantly related species suggested that it was not necessarily a property of particular plants.</p>
<p>Then, around the year 2000, Australian researchers determined that virtually all of the volatile organic compound-removing ability of potted plants resided <a href="http://www.jhortscib.org/Vol77/77_1/21.htm">in the pot</a>. It was the normal bacteria of the potting mix that took up the volatile organic compounds. </p>
<p>But the plants are not superfluous: <a href="http://link.springer.com/article/10.1023%2FB%3AWATE.0000038896.55713.5b">experiments</a> where the plants were removed leaving only the potting mix showed a gradual loss of performance over a few weeks. </p>
<p>The plants supply the soil bacteria with key nutrients that sustain their viability and health. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=550&fit=crop&dpr=1 600w, https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=550&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=550&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=691&fit=crop&dpr=1 754w, https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=691&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/26416/original/xvwh4r4q-1372397037.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=691&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Plants as well as the bacteria in the potting mix contribute to the removal of volatile organic compounds.</span>
<span class="attribution"><span class="source">Rachel Carter</span></span>
</figcaption>
</figure>
<p><a href="http://link.springer.com/article/10.1007%2Fs11270-006-9124-z">More recent experimentation</a> has monitored the background concentrations of volatile organic compounds in offices with and without plants over some weeks. These findings indicate that even three potted plants in an average-sized office will reduce airborne volatile organic compounds to an extremely low level.</p>
<p>Plant-mediated CO<sub>2</sub> removal has received less research attention, primarily because this pollutant is well controlled by modern air conditioning systems. But field trials have shown that between three and six medium-sized plants in a non-air conditioned building can reduce CO<sub>2</sub> concentrations by a quarter.</p>
<p>The question now is whether we should be using air conditioning for ventilation purposes at all when indoor plants can do the work for us at a greatly reduced cost. But a lot more work is needed before we get the complete picture of the potential of plants to deal with indoor CO<sub>2</sub>. </p>
<p>The growing push for more sustainable buildings should give this field impetus.</p>
<h2>Indoor plants at work</h2>
<p>Environmental psychologists have long proposed that indoor plants can improve workplace performance and satisfaction. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=904&fit=crop&dpr=1 600w, https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=904&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=904&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1135&fit=crop&dpr=1 754w, https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1135&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/26417/original/9fq8jnd8-1372397104.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1135&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Improved mood, concentration, and creativity are all benefits of keeping indoor plants.</span>
<span class="attribution"><span class="source">Charlie Tetiyevsky</span></span>
</figcaption>
</figure>
<p>Having a plant in the office has positive outcomes, including an improved emotional state, reduced negative mood states, reduced distraction, increased creativity, and improved task-performance. </p>
<p>Many studies have related these effects to the idea of <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2760412/">biophilia</a>, which suggests being near a plant returns us, in some small way, to our evolutionary beginnings in the prehistoric forest. </p>
<p>Far from being just another form of interior decoration, plants are important for maintaining the habitability of the indoor environment, where most of us spend the great majority of our lives. </p>
<p>We know plants have always maintained air quality and kept us happy and productive. Dramatically rising energy costs and a growing emphasis on sustainability should make us consider the role plants will play in the indoors of the future.</p>
<p><strong>Acknowledgement</strong>: Mr Peter Irga and Professor Margaret Burchett contributed to this article.</p><img src="https://counter.theconversation.com/content/15339/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Much of the research this article is based on has been funded by various bodies associated with the nursery industry, including Ambius, The Interior Plantscapers’ Association, Horticulture Australia Limited and the Dutch Flower Foundation.</span></em></p>It may come as a surprise but air pollution levels indoors are almost always higher than outside, even in busy city centres. Even more surprising is that indoor plants have the ability to mitigate high…Fraser R Torpy, Lecturer, School of the Environment, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.