Managing Tar Spot on Maple Trees: Leaf Removal and Fungicide Timing

Tar spot is a common fungal disease on maples that causes black, tar-like spots on leaves. While it rarely kills the tree, it can be unsightly and weaken the plant over time.

Cultural Control

Removing spotted leaves from the tree (if practical) and raking up fallen leaves reduces the overwintering inoculum. This simple step can significantly lower disease pressure next spring.

Fungicide Application

Apply a fungicide as soon as leaf buds begin to swell in spring, followed by a second application 7–10 days later. This protects new foliage from infection. Choose a product labeled for tar spot on maples and follow label rates.

Long-Term Management

Combine leaf cleanup with timely fungicide sprays for best results. The disease is primarily aesthetic, so treatment is optional for mature trees in natural settings.