Light burn (light stress)

Top leaves nearest the light bleach pale or white, or turn yellow while lower leaves stay green. Raise or dim the light.

Symptoms

• Top leaves nearest the light bleach pale, white or yellow while lower leaves stay green.
• Leaves curl upwards.
• Crispy, dry tops.

Quick checks

• Is the damage only at the top, closest to the light?
• Check the LED maker's hanging guide.
• Back-of-hand test at the top of the plant for 30 seconds.

How to fix it

1. 1
   Environment

   Raise or dim the light

   Follow the LED maker's distance guide and dim if the light is adjustable.

2. 2
   Environment

   Check heat too

   Bring the canopy into 20–27 °C.

3. 3
   Monitor

   Judge by new growth

   Bleached leaves won't recover; watch new growth.

Likely causes

• Light hung too close, or set too bright for the stage.
• Plant growing up into the light after the flower stretch.
• Heat at the canopy adding to the stress.

What to avoid

• Don't treat it as an iron deficiency: iron yellows new leaves throughout, not just at the top near the light.
• Don't change the light schedule by hand.

Prevention

• Raise the light as the plant grows, especially through the early flower stretch.
• Use the maker's guide.

Monkey products that can help

Stress

Can help the plant cope with abiotic stress; support only.

2 ml per 10 L every week. Always add it to the water first and mix thoroughly before adding anything else.

View product →

Products support a healthy plant. They don't replace fixing the cause.

When to get help

If tops keep bleaching at the maker's recommended distance, email info@monkeynutrients.co.uk with your light model and distance.

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