Horsechestnut: Leaf scorch - Horse Chestnut Leaf Scorch

Biology
Leaf scorch often occurs on a variety of trees (including horse-chestnut) in central and eastern Washington, and sometimes western Washington during the summer. It usually arises after periods of unfavorable weather or stress, such as drought, heat, and dry winds. Generally, irregular areas along leaf edges and between veins become bronzed. After a while, the tissue dries out and browns. Dead tissue progresses from the margin of the leaves to the veins as stress continues. From time to time, small angular brown specks appear between leaf veins. Twigs and branches may then die back.
Management Options
Select Non-chemical Management Options as Your First Choice!!
Avoid root injury when digging; if you must sever roots, make a clean cut and prune the tree to maintain balance between root and foliage mass.
Check for other diseases such as canker and vascular wilts, which may actually be producing the symptoms.
Irrigate so that water penetrates deep into the root zone. Short, frequent watering intervals do not produce a deep, strong root system or good tree health.
Limit use of de-icing salt near the tree, and check for and correct leaks in sewer or gas lines.
Remove dead branches if they appear.
Select favorable locations with adequate soil conditions for young trees; separate roots so they will spread to form a wide base and use more soil.

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