Why Your Plants Are Getting Sunburned (Sunscald)
Sunscald happens when plants move suddenly from shade to full sun. Leaves bleach, crisp, and die. Introduce sun gradually.
Signs of Sunscald
- Leaves look bleached white or papery
- Brown, crispy patches
- Damage on sun-facing side
- Appears within 1-2 days of move
The Fix
Immediate: Move to indirect light. Remove fully dead leaves. Water gently.
Long-term: Introduce sun gradually over 7-10 days.
The Hardening Off Process
| Day | Time Outside | Conditions |
|---|---|---|
| 1-2 | 1 hour | Shade |
| 3-4 | 2 hours | Morning sun |
| 5-6 | 4 hours | Morning sun |
| 7-8 | 6 hours | Most of day |
| 9-10 | Full day | All conditions |
Which Plants Are Sensitive
| Plant | Sensitivity |
|---|---|
| Lettuce | High |
| Basil | Medium |
| Tomatoes | Medium |
| Peppers | Medium |
| Zucchini | Low |
| Sunflowers | Low |
Common Questions
Can sunscalded leaves recover? No. Damaged leaves won’t heal. But new leaves will be fine.
Should I remove sunscalded leaves? Only if fully dead. Partially damaged leaves still photosynthesize.
Will my plant survive? Yes, if the stem and roots are fine.
How do I prevent it? Hardening off.
Does sunscald happen indoors? Rarely. But moving from indoors to a sunny window can cause it.
Is it the same as heat stress? Related, but different. Sunscald is light damage. Heat stress is temperature damage.