How to Manage Early Browning of Chestnut Tree Leaves: Identifying and Treating Chestnut Blight

If the leaves of your chestnut trees are turning brown early, it is important to assess the situation carefully, as this could indicate a problem such as chestnut blight, or other issues like environmental stress or pests. Here are steps you can take:

Inspect the Trees

Check for signs of chestnut blight:

Cankers on the bark, wilting leaves, and premature leaf drop. Look for orange-colored spores or lesions on the bark.

Examine the leaves for any signs of pests or diseases:

Holes, webbing, or discoloration.

Assess Environmental Factors

Consider any recent changes in weather:

Drought or excessive rain, which could stress the trees.

Ensure that the trees are not competing with other plants for nutrients or water:

Consult a Professional

If you suspect chestnut blight or are unsure, it is wise to consult a local arborist or extension service. They can provide a proper diagnosis and recommend treatment options.

Prune Affected Areas

If you find cankers or dead branches, prune them away to prevent the spread of disease. Make sure to disinfect your pruning tools between cuts.

Maintain Tree Health

Ensure your trees are well-watered and mulched to reduce stress. Proper fertilization can also help improve their health.

Monitor for pests and apply appropriate treatments if necessary.

Consider Resistant Varieties

If chestnut blight is confirmed and your trees are heavily affected, consider planting resistant varieties in the future.

Report Findings

If you confirm chestnut blight, report it to local agricultural authorities as it can help in managing the disease in the area.

Is the tree located in the lawn area?

If so, it may be overwatered. Most fruit trees need less water than ornamental trees.

If you have one of the susceptible chestnut species, it's certainly a possibility that it's chestnut blight, a canker disease caused by a fungus Cryphonectria parasitica.

For American chestnut species, see the following symptoms:

Flagging, the yellowing and dying of individual branches. Dead leaves that hang onto branches over the first winter. On young trees and juvenile branches of mature trees, cankers appear as yellowish to reddish areas in the bark around branch crotches. These cankers can girdle and kill a branch within a few weeks. On mature trees, cankers are initially imperceptible unless the bark is stripped off. Later, as the canker expands, the bark swells and cracks, eventually falling off. Yellowish brown fruiting bodies may be visible on the surface of the bark around the canker or in the cracks in the bark. In American chestnuts, the trunk is eventually girdled, which can occur within a few weeks for young trees and within a few years for mature trees. Generally, few last longer than four years. Suckers usually shoot up from the surrounding roots of American chestnuts, providing a constant supply of susceptible tissue for the pathogen's continued existence. This suckering does not occur in other species.

If it is indeed chestnut blight, what you do about it depends on how destructive it is and if your trees are serving as disease vectors for other chestnut trees in the area. There are some methods that can be used to combat the disease on a few trees: the soil compress method, using biological control against the fungus, hypovirulence, and chemical control.