The maple tree is infected by bacterial leaf scorch. The bacterium Xylella fastidiosa causes bacterial leaf scorch. The disease can be managed by a combination of factors.

• Rake up and destroy fallen leaves before the first snowfall to eliminate locations where diseases can survive to re-infect the plant the following growing season.
• Prune trees or shrubs to increase light penetration and improve air circulation throughout the canopy.
• Wet conditions promote disease, so water trees at the base and be careful not to splash water on leaves. A drip or soaker hose works best for this. Avoid sprinklers.
• Reduce stress to your tree:
• Water your tree throughout the growing season so that the top 6 to 8 inches of the soil is moist, especially during dry summer periods.
• Soil should be allowed to dry before watering again.
• Maintain a 3- to 4-inch-deep layer of mulch around your tree.
• Do not mound the mulch around the trunk of the tree but lay a flat layer with at least a 2-inch space between the mulch and stem to allow for air movement.
• Annually reapply mulch and inspect to ensure levels are maintained.

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