bobm
Garden Master
Most of crab apple trees in our area including ours are being attached by Vetiro omeqialis or apple scab this very wet year. The leaves get little brown holes then sart to curl up and later drop. . Most of the trees will refoliate and survive. The trees need energy to help them survive, so fertilisers are in order. There is nothing that you can treat for it , but you can help with preventing it with fertilizer, clean up leaves and dead twigs in the fall.