
The signature midsummer yellow-and-drop that panics owners is apple scab defoliation, and the tree refoliates the following spring — it is a cultivar problem, not a death sentence. Real decline reads on a different schedule: thin, sparse foliage in spring rather than late summer, a shrinking flower load year over year, dead scaffold limbs, and trunk cankers or borer holes on a tree past 40 years.
Crabapple is the most-planted small tree in central Indiana subdivisions and it generates more "is my tree dying?" calls than anything else its size — because scab-susceptible cultivars go yellow and defoliate in July and August every single year while remaining perfectly alive. Most of these calls end in a spray program or a replacement conversation, not a removal.