Black mold on tree limbs and branches - Ask Extension
We have a tree (not sure what kind but not a fruit tree). It's probably 25 - 30 feet tall. Seeing a black mold or fungus on all the branches but seems...
Knowledgebase
Black mold on tree limbs and branches #870047
Asked May 25, 2024, 11:18 AM EDT
We have a tree (not sure what kind but not a fruit tree). It's probably 25 - 30 feet tall. Seeing a black mold or fungus on all the branches but seems to be only the top side of branches. Underside of branches appear to be normal. Do not see anything on the leaves.
Would like to know what it is and how to treat it.
Story County Iowa
Expert Response
Its not possible to know for sure from the photos alone, but from your description and what I can see in the photos, I suspect this is sooty mold. Sooty mold grows on honeydew secreted from insects like scale, mealybug, and aphids. If this tree has an infestation of these insects or had one in the past, than that would explain the presence of the sooty mold.
The sooty mold is of little consequence to the plant, however, the insects that caused the sooty mold would be. Inspect the plant carefully for signs of scale or aphids. More information about these pests (and how to manage them) is below.
https://entomology.ca.uky.edu/ef103
https://yardandgarden.extension.iastate.edu/encyclopedia/woolly-aphids
https://yardandgarden.extension.iastate.edu/encyclopedia/scale-insects
Further questions can be directed to your local county Extension office. This local resource is very helpful since they are familiar with trends and issues in your part of the state. Click on this link to get connected directly with a staff person in your county Extension office and ask your gardening question. https://yardandgarden.extension.iastate.edu/ask-gardening-question.
The sooty mold is of little consequence to the plant, however, the insects that caused the sooty mold would be. Inspect the plant carefully for signs of scale or aphids. More information about these pests (and how to manage them) is below.
https://entomology.ca.uky.edu/ef103
https://yardandgarden.extension.iastate.edu/encyclopedia/woolly-aphids
https://yardandgarden.extension.iastate.edu/encyclopedia/scale-insects
Further questions can be directed to your local county Extension office. This local resource is very helpful since they are familiar with trends and issues in your part of the state. Click on this link to get connected directly with a staff person in your county Extension office and ask your gardening question. https://yardandgarden.extension.iastate.edu/ask-gardening-question.
