Troubleshooting
Cashew problems — and how to fix them
Cashew (Anacardium occidentale) 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.
Caustic nutshell oil (CNSL)
The raw shell oozes urushiol-like oil that burns skin and must never be inhaled when roasting. Always roast nuts before handling or eating; wear gloves when processing.
Frost damage
Frost-tender and intolerant of cold; even a light frost kills young trees. It can only be grown outdoors in frost-free tropical or subtropical zones.
Anthracnose and powdery mildew
Fungal diseases attack flowers and young nuts in humid, wet weather, slashing yields. Improve airflow and remove affected panicles.
Tea mosquito bug and other pests
Sap-sucking bugs damage shoots, flowers and developing nuts in many growing regions; monitor flowering flushes closely as these set the crop.
Prevent cashew problems before they start
Most cashew issues are care-mismatch, not bad luck. Dial in the basics:
Looking for cashew in general rather than its problems? Read the full cashew care guide — light, water, soil and feeding.
Cashew problems — FAQ
Why is my cashew caustic nutshell oil (cnsl)?
The raw shell oozes urushiol-like oil that burns skin and must never be inhaled when roasting. Always roast nuts before handling or eating; wear gloves when processing.
Why is my cashew frost damage?
Frost-tender and intolerant of cold; even a light frost kills young trees. It can only be grown outdoors in frost-free tropical or subtropical zones.
Why is my cashew anthracnose and powdery mildew?
Fungal diseases attack flowers and young nuts in humid, wet weather, slashing yields. Improve airflow and remove affected panicles.
Why is my cashew tea mosquito bug and other pests?
Sap-sucking bugs damage shoots, flowers and developing nuts in many growing regions; monitor flowering flushes closely as these set the crop.