Why Are My Crabapple Leaves Yellow, Brown, and Spotted?

Newly transplanted crabapples often show a few yellow leaves from transplant shock. Keep the tree well-watered (check soil moisture an inch down) for the first season until roots establish.

If spots are olive-green turning black and velvety, with yellowing and mid-summer leaf drop, it's apple scab — a common fungal disease favored by humid, warm springs. Susceptible trees need preventive fungicide sprays starting just before bloom in early spring, repeated per label. The best long-term fix is planting a scab-resistant cultivar.