I finally discovered what the heavy black stuff on my deck and concrete drive is. It's sooty mold. All I have around is 100 year old, maple, oak and pine trees. How do I get rid of the aphids (if that's the problem) from such large plants? It took me 5 hours of constant high pressure cleaning to get most of the black off my 8 X 20' deck. A large driveway is still covered and there is a lot of sticky stuff on my car and husband's. Smaller plants such as hostas have quite a bit also. Who do I call to clean the trees off?
Certified GKH Gardening Expert
Neem oil can be used to get rid of the pests as well as the fungus This article will help: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
An arborist can help, especially if pruning becomes necessary, but you should be able to mix the neem oil in a sprayer to treat the trees.