FAQ – Could this balsam rust become another Ash dieback?

No. Chalara, the disease that causes Ash dieback is an unwelcome invader that threatens a key native tree species. However, if for a moment we were to pretend that ash was an unwanted invasive tree then Chalara would be a great biocontrol agent as it is effective and will only attack ash. Effectively, what we have is a ‘Himalayan balsam dieback’ fungus, and like Ash dieback, it is highly host specific.