Troubleshooting
American Chestnut problems — and how to fix them
American Chestnut (Castanea dentata) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Chestnut blight
The fungus Cryphonectria parasitica girdles the trunk, causing orange cankers and dieback above the lesion. It is the disease that wiped out the species' wild range; grow blight-resistant hybrids where possible.
Poor or empty nuts
Chestnuts are self-incompatible, so a single isolated tree sets few filled nuts. Plant two or more genetically different seedlings within about 30 m for cross-pollination.
Chestnut weevil
Larvae bore into developing nuts, leaving them riddled and inedible. Prompt harvest of fallen burs and hot-water or cold treatment of nuts reduces infestation.
Ink disease / root rot
Phytophthora in wet or poorly drained soil rots the roots and collar, causing wilting and black, inky bark stain at the base. Plant on free-draining ground and never let the crown sit in water.
Prevent american chestnut problems before they start
Most american chestnut issues are care-mismatch, not bad luck. Dial in the basics:
Looking for american chestnut in general rather than its problems? Read the full american chestnut care guide — light, water, soil and feeding.
American Chestnut problems — FAQ
Why is my american chestnut chestnut blight?
The fungus Cryphonectria parasitica girdles the trunk, causing orange cankers and dieback above the lesion. It is the disease that wiped out the species' wild range; grow blight-resistant hybrids where possible.
Why is my american chestnut poor or empty nuts?
Chestnuts are self-incompatible, so a single isolated tree sets few filled nuts. Plant two or more genetically different seedlings within about 30 m for cross-pollination.
Why is my american chestnut chestnut weevil?
Larvae bore into developing nuts, leaving them riddled and inedible. Prompt harvest of fallen burs and hot-water or cold treatment of nuts reduces infestation.
Why is my american chestnut ink disease / root rot?
Phytophthora in wet or poorly drained soil rots the roots and collar, causing wilting and black, inky bark stain at the base. Plant on free-draining ground and never let the crown sit in water.