Wind Burn

Updated Sep 27, 2018

by Nebula Haze

Most indoor cannabis growers use fans to blow air around within the grow area. This creates a nice breezy environment that cannabis plants love. But sometimes there can be too much breeze!

Be Careful! Too Much Wind Causes Clawed Leaves and Sometimes Spots

When there’s too much breeze, the affected marijuana leaves will start getting “wind-burned.”

Windburnd cannabis leaves are clawing hard

Another example of cannabis wind burn in the flowering stage – they plant had twisted, unhappy leaves where the fan was blowing on them. It alsmost looks like root problems!

Example of cannabis wind burn - the leaves are twisted and pointing up

Wind-burned leaves are often curved under and form “claws.” They can look like they’re droopy from overwateringunderwatering, or possible a nitrogen toxicity, but you know you’ve got wind-burn when the leaves in front of the fan are clawing, and leaves further away from the fan look fine.

These clawed leaves were wind-burned

Just for reference, here’s what too much wind/fan looks like!

Too Much Fan!

Sometimes too high levels of wind can cause other unusual problems on the affected leaves, such as brown or bronze spots that almost look like burn marks. These are the result of the leaf not being able to fulfill all its normal processes.

Example of cannabis wind damage causing brown or bronze spots that look like burns on the leavesThis cannabis leaf has brown / bronze spots that look like burns - it's not a nutrient deficiency, it's actually caused by wind burn!

A closeup of those wind burn leaf spots – not bugs, not a nutrient deficiency!

These spots on this marijuana plant are actually caused by wind burn

Placing Fans

  • Ideally you’d like a nice breeze surrounding the main canopy, which means you want air blowing above and under the plants.

  • All the leaves should be gently rustling in the best-case scenario, but should never be waving around.

  • Don’t point a strong fan directly at a plant, because too much wind can start to damage the leaves and stems. Sometimes if you have a small space it’s better to point the fan at the wall than directly at the plants.

  • After placing fans, check around the grow area to make sure that all parts get a slight breeze. If you feel stagnant air or a lack or breeze, you may want to adjust your fans.

  • Small oscillating fans are great for the grow space since they’re cheap and can be used to provide a nice gentle breeze to a relatively wide area without blowing on any one part too long.

Growing cannabis circulation diagram

If you cannot get rid of the clawing symptoms from marijuana wind burn, please consult our 7-Step Remedy to 99% of Cannabis Growing Problems for more help!

Leaf Color

  • Brown or Dark Spots
  • Dark or Purple Leaves
  • Edges Appear Brown or Burnt
  • Yellow Leaves - New Growth

Leaf Symptoms

  • Abnormal Growth
  • Leaf Edges Appear Burnt
  • Leaves Curl Under
  • Leaves Curl Upwards
  • Spots
  • Twisted Growth
  • Upper Leaves / Newer Growth Affected
  • Wilting / Drooping

Plant Symptoms

  • Leaves Curl Under
  • Leaves Curl Upwards
  • Plant Wilting / Drooping
  • Red or Purple Stems
  • Twisted Growth

Root Symptoms

  • Slow Growing
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