Greetings all, I have a question about red maple leaves and their herbicidal behaviour. A Toronto Star article says that the red leaves contain anthocyanin, which is produced in the fall. When the chlorophyll breaks down, the yellow colours emerge. But the reds are caused by the production of anthocyanin - which also turns out to be a natural herbicide. (Pg F4 of Oct. 23rd issue for folks who read it, sorry I couldn't find it online for every one else.) Tests were performed using 4 different types of leaves green beech, yellow beech, green maple and red maple leaves. Lettuce seedlings came into contact with green and yellow leaves sprouted fine, however the seedlings that came in contact with the red maple leaves were inhibited. The theory is that Maple leaves stop growth of other plant seedlings and saplings, so it's own will have an advantage. My questions: 1) When the red leaves dry up and turn brown - do they lose the anthocyanin? 2) If not - at what point is maple leaf content in a backyard leaf mulch going to cause risk to flower bed seedlings and saplings? Thanks for your thoughts.