Crataegus oxyacantha a.k.a. Some cultivars are especially susceptible to the black spot fungus, which may defoliate the tree by July. Plant in wide planting strips. Juglans nigra, J. regia. J. nigra roots are destructive.
Roots are particularly destructive to sidewalks.
They need an especially wide planting strip. Destructive to paving, roots heave sidewalks. They are susceptible to anthracnose diseases. Crownright' is a variety that should be used to avoid this problem. In Seattle, it is highly susceptible to canker attack, which is often fatal.