light excess

What you’re seeing

Bleached or washed-out foliage, compact or hardened leaves, leaf edges turning tan in high exposure, substrate drying very quickly, or photobleaching near a window hotspot.

What it is

Chronic high-light stress. Overall intensity is higher than the plant prefers. Not necessarily burn, but cumulative stress from too much light duration or power. Full sun is suitable for sun-loving plants (succulents, herbs, cacti); medium or bright-indirect light suits many tropicals like pothos, philodendrons, or peace lilies; low light suits shade specialists like ZZ and snake plant.

Is action needed?

Often yes—especially near south/west windows or under strong LEDs.

How to confirm

Shadow test: Crisp, dark shadows for many hours indicate strong light.
Pattern: Leaves nearest the light are paler or roughened; shaded leaves look normal.
Quick fix test: After moving a bit back or adding a sheer curtain, new leaves grow more normally.

What to do

Soften exposure: Add sheer curtains, move 0.5–2 m (1.5–6 ft) away, or shift to an east window.
Adjust grow lights: Raise the fixture or reduce photoperiod to 10–12 h.
Watering: Monitor more frequently; bright light increases demand, but avoid overcompensating with constant wetness.
Acclimate gradually when increasing light in the future.

Prevention tips

Introduce brighter light over 1–2 weeks.
Use light meters or apps to gauge intensity; record what works for your plant.

Sunburn/sunscald cause sharply defined necrotic patches; general light excess is more uniform fading.
Nutrient deficiency can also pale leaves—check light placement first.