Crab apple problem
We have a mature (approximately 25 years old) crab apple tree in the middle of our front yard (east facing). It gets sun from early morning until about 2 pm. Leaves on the branches on the under side of the tree are turning yellow, which is not normal for this time of year. Gradually the leaves turn brown and fall off. I have just started being aware of the problem, but I guess it could have been there for about 3 weeks. Some have some ragged edges, but it does not appear that insects are causing this to happen. Is there anything we can do to prevent losing the whole tree?
Anne Arundel County Maryland
In general, Crabapples are subject to several fungal diseases such as scab, rust, etc. These diseases are unattractive but do not kill the tree.
The best recommendation is to plant resistant varieties. Rake and destroy any fallen leaves and fruit. See our publication on ornamental fruit trees http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG93_IPM_Series_Orna...