# Wind burn

> Leaf damage from a fan blowing directly and constantly on the same leaves: curled, clawed or crispy leaves on the side facing the fan, sometimes with brown, dried patches.

- Canonical: https://genetixbay.com/knowledge/glossary/wind-burn.html
- Also written: windburn, fan burn, wind damage
- Glossary category: Environment and light · Evidence: Grower practice
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Wind burn is local damage on leaves that sit in a constant direct airflow. The leaves lose water faster than the roots can supply it, so they curl, claw, rattle or turn crispy, typically only on the side of the plant facing the fan. Airflow changes [leaf temperature](https://genetixbay.com/knowledge/glossary/leaf-temperature.md) and [transpiration](https://genetixbay.com/knowledge/glossary/transpiration.md) (Nelson and Bugbee 2015); the term itself is *Grower practice*.

## In practice

The giveaway is position: damage on one side, matching the fan, while the rest of the plant is fine. Angle fans to move air across and above the canopy so leaves flutter gently, use [oscillating fans](https://genetixbay.com/knowledge/glossary/oscillating-fan.md), and keep them off the [colas](https://genetixbay.com/knowledge/glossary/cola.md).

## Don't confuse with

- **Heat stress**: [tacoing](https://genetixbay.com/knowledge/glossary/taco-leaf.md) across the top of the canopy wherever it is hottest.
- **Leaf clawing**: tips hooked down across the plant, linked to nitrogen or water.
- **Underwatering**: the whole plant goes limp.

## Related terms

[Airflow](https://genetixbay.com/knowledge/glossary/airflow.md), [Oscillating fan](https://genetixbay.com/knowledge/glossary/oscillating-fan.md), [VPD](https://genetixbay.com/knowledge/glossary/vpd.md), [Transpiration](https://genetixbay.com/knowledge/glossary/transpiration.md)

## Read more

- [Airflow: air exchange, canopy air speed and fan placement](https://genetixbay.com/knowledge/environment/airflow.md)
- [Heat and light stress: taco leaves, bleaching and foxtails](https://genetixbay.com/knowledge/environment/heat-light-stress.md)

## Sources

1. Nelson JA, Bugbee B, 2015. Analysis of environmental effects on leaf temperature under sunlight, HPS and LEDs. PLoS ONE 10(10): e0138930. https://pmc.ncbi.nlm.nih.gov/articles/PMC4598144/