We have a crab apple that gets apple scab. We will spray this spring and I...
We have a crab apple that gets apple scab. We will spray this spring and I will rake all the leaves away from the tree. Is there anything we can spray on the ground where the leaves were to kill off fungus but not harm the tree.
Washington County Minnesota
Thank you for your question.
Apple scab is a fungus and is spread via wind and rain, so weather conditions affect the severity of the disease. Apple scab spores appear on leaves and overwinter on fallen leaves, so applying fungicide to the soil will not make a difference and thus is not recommended. Selecting resistant varieties of crabapple trees for your landscape is the best way to reduce the occurrence of this disease. Sanitation in the form of cleaning up the fallen leaves and fruit is also recommended.
Here is an excellent publication from U of M Extension on pest management for apples. It includes the following section on apple scab.
I hope this is helpful. Thank you again for contacting Ask an Expert.