NEW: Strain ShopBrowse strains
Environmental StressSerious

Light Burn on Cannabis

Light burn happens when your grow light is too intense or too close. It bleaches top leaves white-yellow and can ruin cola tips.

What it looks like

  • Top leaves turning yellow or bleached white (starts at tips)
  • Damage only on leaves closest to the light
  • Buds may bleach white instead of maturing
  • Foxtailing (new bud growth from cola tops)

Quick diagnostic checks

1Raise the light 4 inches as first move
2Use a PPFD meter or app to confirm intensity
3Target: 600-800 μmol in veg, 800-1000 in flower (no CO2)

Measure before you treat

Plant diagnostic essentials

Compare all diagnostic tools →

These tools help confirm the cause of light burn before you change nutrients, watering, or the environment.

Govee Bluetooth Hygrometer

Track temperature and humidity trends instead of guessing from one reading.

Check price on Amazon

BN-LINK Digital Timer

Keep light schedules consistent and prevent accidental dark-cycle interruptions.

Check price on Amazon

VIVOSUN pH and TDS Meter Combo

Check root-zone pH and nutrient strength before changing a feeding plan.

Check price on Amazon

Save the light burn recovery plan

Get a concise recovery checklist plus the follow-up checks that show whether your fix is working.

No spam. Unsubscribe anytime.

Causes ranked by likelihood

1. LED too close to canopy

Most common

Signs

  • Light within 18" of canopy on a 3000K+ LED
  • PPFD above 1000 at canopy

Fix

  • Raise LED to 18-24" from canopy
  • Dim to 75-80% if your light has a dimmer
  • Measure PPFD with a meter or app

⚠️When to worry

Light-bleached buds are unsellable. Fix before flower for best results.

Not sure what you're looking at?

Upload a photo of your plant and our AI will diagnose the problem in seconds — free.

Open AI Plant Diagnosis →

Keep the plant recovery checklist handy

Get the diagnostic order, recovery checkpoints, and prevention reminders by email.

No spam, ever. Unsubscribe anytime.