Chestnut Blight

Rapidly multiplying fungal disease arriving from Asian nursery stock, killing 3.5 billion American chestnuts by 1940. Formerly the tallest trees on the east coast, making up 50% of eastern hardwood forests.

Latin Name

Endothia parasitica
aka Cryphonectria parasitica

Trees Affected

American chestnut, European chestnut, Chinese chestnut (resistant), minor infection in some oak species

Threat to Trees



Rapid, usually causing mortality of everything above the canker within one growing season due to susceptibility to foreign disease


Wind, splashing rain, birds, and other animals carrying fungal spores to small cracks and wounds in the bark.

Signs & Symptoms

Small cankers at wounds and cracks which expand and girdle the stem, most common in seedlings


Older trees are more resistant to blight and can survive in spite of blight, but are not immune. Environmental stresses will break down this resistance, including climates and high elevations. Even in areas that have been completely cleared by fungal blight, the disease still remains in areas where all trees have been killed.

Domestic Origins

New York, ~1900

Geographic Location

Maine to Georgia

Photo Credits