Shothole (Coryneum Blight)

You'll spot small brown lesions with shot-like holes on Japanese apricot (Prunus mume) leaves, especially on older foliage. This fungal blight shows up in spring through early summer during cool, wet weather. The disease matters because it can defoliate trees and stunt new growth. Prune out infected buds and twigs, rake fallen leaves, and avoid overhead watering. Sulfur or chlorothalonil applied at petal fall helps manage severe infections in the PNW.

Remove blighted tissue promptly, cutting well below visible symptoms. Improve air circulation by thinning dense growth. Avoid overhead watering, especially during bloom and new growth periods when tissues are most susceptible. For recurring problems, preventive fungicide applications timed to protect new growth can reduce infection, but cultural controls should be your first approach.