Why Your Seedlings Have White Spots (3 Causes)
White spots on seedlings are usually powdery mildew, sunscald, or water spots.
The 3 Causes
Cause 1: Powdery Mildew
Texture: Powdery, fuzzy, spreads. Fix: Improve airflow.
Cause 2: Sunscald
Texture: Papery, dry, bleached. Fix: Move back to indirect light.
Cause 3: Water Spots
Texture: Smooth, no texture change. Fix: Wipe off.
How to Tell Them Apart
| Texture | Cause |
|---|---|
| Powdery, spreads | Powdery mildew |
| Papery, bleached | Sunscald |
| Smooth, no spread | Water spots |
What to Do
- Touch it. Powdery → mildew.
- Check spreading. Spreading → mildew.
- Check location. Sun side → sunscald.
Common Questions
Are white spots harmful? Water spots: no. Sunscald: cosmetic. Mildew: yes.
Can sunscald recover? Damaged leaves won’t. New leaves are fine.
Will water spots hurt the plant? No. Just cosmetic.
How do I prevent powdery mildew? Airflow, avoid wetting leaves.
Should I remove affected leaves? Only if powdery mildew.
Does tap water cause spots? Sometimes, if it’s hard water.