How do I get rid of black fly? It is mostly on the tops of the branches and can I prune the tree now, as it is growing very fast and tall? This is the first year of planting the cherry tree. It was supposed to be container grown. But it kept falling over so put it in the ground.
I would recommend trying neem oil. It is effective against both harmful insects and fungus, and it's very safe to use. Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm