Dry, torn or curled leaves facing a fan
Only leaves in the direct airstream; they flutter constantly, then dry at the edges, curl and tatter..
- Also called
- wind burn
- fan burn
- leaves shredded by fan
- leaves clawing near the fan
- windburn
Likely causes, most likely first
Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.
LikelyWind burn from a fan blowing directly on leaves
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.
How to confirm it
- 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.
Look for
Leaves on the fan side curled, thin, dry-edged or torn; the same leaves on the far side healthy..
The full guide: Airflow: air exchange, canopy air speed and fan placement
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.
