I agree, you should be careful...>For example, I have some
trees(which will hopefully be removed this winter) which get a horrible black mold on their leaves every summer. It starts around July. The big problem is that it spreads to the surrounding
plants. Which is why I am having them cut down....But I would never, never used them in part of my composting system..Instead, I got my neighbors leaves from down the street. They have lots of healthy
trees in their yard and don't garden so they were glad for me to take them.....Good Luck, jan