For the past 20 years we have been troubled by hundreds of saplings from 6 mature aspens at the bottom of a fairly large garden. They come up all over the place, in the lawn, under shrubs, you name it. We wanted to fell the trees and I did some research and found that aspens have particularly strong ability to regenerate from roots if the tree is damaged. However, studies have shown that felling the trees then knocking ecoplugs of glyphosate into the stumps kills the roots and prevents sapling regrowth. So we had professional tree surgeons in to do that last autumn. Now we are finding dozens of saplings appearing, worse than before, which looks as if the treatment has not worked as we had hoped. Might the poison start to work now that spring growth is well underway or do we need to do something else?