Invasive species lead to loss of native plants, impede river flow and cost the nearly £2 bn a year to control. So what can be done?
Why home owners shouldn't panic over knotweed on their property.
It's nearly impossible to kill, so we need to start working with Japanese knotweed to control it.
Beeches are 'non-native' to Scotland because they got there less than 7,000 years ago. No, really.