Black Sooty Mold

Black sooty mold is actually the secondary effect of a problem you may have with your tree.  The actual problem with the tree is a large sucking insect population of scale. They suck the nutrients out of your tree.  After they suck the nutrients out, they frass (poop) and their excrements are actually mostly sugar.  Ant activity will increase in your tree because of this sugary excrement and the rest will blow on the leaves and all over the tree.  After a little while, black sooty mold will start to develop on leaves and branches. This appears as a black substance that can be easily rubbed off with your fingers. This black substance not only makes your tree look bad, but if it is extreme enough, will cover your leaves and stop photosynthesis.  This can slow growth and leaves can die.  So your tree not only loses nutrients from the insects, it can’t photosynthesize to create more energy.              

This problem can be easily remedied if seen.  By removing the pest, the black sooty mold will eventually go away.  Some people try to power wash their tree to remove the black sooty mold, but this can cause damage to leaves and branches.  Warm soapy water will remove the mold if the area is small enough to handle.  Call to have your tree evaluated and the pests controlled any time of the year and your local Arborist will let you know the best methods for control.