Light

Aloe Vera Sunburn — White or Brown Patches from Too Much Sun Too Fast

Aloe Vera (Aloe vera)

Symptoms

  • white or pale tan patches on leaf surfaces
  • patches appearing on the sun-facing side of leaves
  • patches developing after moving to brighter location
  • patches that don't spread but turn increasingly dry

Causes

Sudden exposure to intense light

Aloe vera that has been living in indoor conditions (even a bright window) has chloroplasts acclimated to that specific light intensity. Moving the plant directly into full outdoor sun — even though Aloe vera is designed for desert sun — overloads the photosynthetic machinery. The chloroplasts bleach, the cells in the overloaded areas die, and white or tan patches form on the sun-facing leaf surfaces. This is photobleaching and photo-oxidative stress.

How to Fix It

  1. 1

    Move the plant to a slightly shadier location — dappled shade or very bright filtered light while it acclimates.

  2. 2

    The sunburned patches will not recover — those cells are dead. The patches are cosmetic and won't spread unless the burn continues. Don't remove the affected leaves unless they're cosmetically intolerable.

  3. 3

    To acclimate to full sun: start in shade; after 5–7 days, move to morning sun only (east exposure); after another 5–7 days, move to morning-and-afternoon sun; then full sun. The gradual increase allows the chloroplasts to upregulate their protective mechanisms.

  4. 4

    Once acclimated, the same intensity of light that caused burn no longer damages the plant. Fully acclimated Aloe vera in full sun rarely burns.

Prevention

  • Acclimate any transition from indoor to outdoor light over 2–3 weeks
  • Start outdoor placement in shaded or filtered sun position
  • Never move directly from a dim room to full direct sun

Quick Summary

PlantAloe Vera (Aloe vera)
CategoryLight
Likely causesSudden exposure to intense light
Fix steps4 steps — see above