# Dry, torn or curled leaves facing a fan: likely causes and fixes

> Dry, torn or curled leaves facing a fan on cannabis is most often Wind burn from a fan blowing directly on leaves. How to tell them apart, the fix for each and what recovery looks like.

Also called: wind burn, fan burn, leaves shredded by fan, leaves clawing near the fan, windburn.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=whole&s=wind-burn

## Likely causes, most likely first

### Wind burn from a fan blowing directly on leaves (Likely)

- Kind: Environment; urgency: Low urgency
- Fix: Aim fans across and under the canopy, not straight at leaves: leaves should rustle, not thrash (roughly 0.3-1.0 m/s at leaf level). Damaged leaves stay damaged. Cannabis-specific evidence is grower observation.
- Recovery: No new damage on the fan side within a week.
- Confirm: Compare with siblings or the same cut: Put the affected plant beside siblings or clones of the same cut in the same conditions. A trait shared by all of a cultivar (purple stems, foxtailing, pale colour) is genetic; a problem on one plant points to its roots, a virus or its genetics; a problem on every cultivar points to the environment or feed.
- Article: [Airflow: air exchange, canopy air speed and fan placement](https://genetixbay.com/knowledge/environment/airflow.md)

## Note

Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.