Ink Spot

Quaking aspen leaves develop dark spots and blotches, occasionally becoming severe. This fungal disorder shows up on native trembling aspen in forested areas. No management is typically needed for landscape trees. In nursery settings, sanitation and spacing help reduce disease pressure.

Leaf spot and blotch diseases are primarily cosmetic on established plants, though repeated years of heavy infection can weaken them. Rake up and remove fallen leaves to reduce the spore load going into the next season. Avoid overhead watering that splashes spores from the ground onto lower leaves. If the problem is severe, protective fungicide sprays during spring leaf emergence can help, but sanitation does more than chemistry for most leaf spots.