Flushing, MI: Why Are the Leaves Falling from My Crabapple Tree?

Apple scab, a fungal disease caused by Venturia inaequalis, is a common issue for both apple and crabapple trees, often seen in Genesee County residential landscapes. The disease starts infecting trees in the early spring, particularly when cool, wet conditions create an ideal environment for fungal growth.

On crabapple trees in Flushing, apple scab presents as dark, olive-green lesions on the upper surface of the leaves. Over time, these spots can darken to brown or black, causing the leaves to curl, distort, or drop prematurely. In severe cases, apple scab can lead to subantial defoliation, weakening the tree and diminishing its overall appearance.

Common Symptoms of Apple Scab Disease:

• Fungal lesions on leaves
• Reduced flowering
• Premature leaf drop, often by mid-summer
• Early season defoliation
• Increased susceptibility to secondary diseases and insect damage
• Branch dieback and gradual decline

To manage apple scab, it’s essential to apply fungicides before the infection begins in spring. As the leaves continue to get larger and new leaves sprout, additional treatments will be needed to protect them. Typically, three applications will provide adequate control for crabapple trees in residential landscapes.

Apple scab is more than just a cosmetic concern; if left untreated, it can significantly impact the long-term health of your crabapple tree.

If your crabapple tree is losing leaves too soon or there are brown spots on the leaves, contact Owen Tree and Lawn Care. A professional inspection familiar with insect and disease pests common in Flushing will be able to determine if the tree has apple scab fungus or if there is something else stressing your tree.