|I live in central Fl and in the winter months on a few of my shrubs a black layer of ash would cover the leaves turning the entire bush black. I can easily rub it off with my finger tip. I have noticed that it is already covered one of the shurbs already. what is this and what can i do to stop it from happening. Thank you,
|Answer from NGA
July 21, 2009
|If the black substance is shiny and can be scraped off with a fingernail, it is sooty mold. This substance is the result of insect feeding higher up in the plant. As insects such as aphids feed, they exude a sticky substance called honeydew. There is just enough sugar content in the excretion to grow mold and the substance is then called sooty mold. Insecticidal soap is effective against aphids so once you get the aphid population under control you shouldn't have any more problems with sooty mold.
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