Why Your Seedlings Are Leggy (Tall and Thin) — And How to Fix It
Leggy seedlings are caused by not enough light. The stem stretches toward the window, weakens, and eventually falls over.
The 3 Causes
Cause 1: Not Enough Light (Most Common)
How to fix:
- Move to a brighter window
- Add a grow light 2–4 inches above the plants
- Rotate pots daily
Cause 2: Light Too Far Away
A light 2 feet above seedlings is useless. It should be 2–4 inches.
Cause 3: Too Warm
High temperatures (above 75°F) speed up stem growth without enough light.
How to Fix Leggy Seedlings
If they’re only slightly leggy:
- Move to stronger light immediately.
- Rotate daily.
If they’re very leggy:
- Repot them deeper — bury the stem up to the first leaves.
- Or start over.
If they’ve fallen over:
- Prop them up with a small stick.
- Move to stronger light.
Prevention
| Factor | What to Do |
|---|---|
| Light | 12–16 hours daily, 2–4 inches from leaves |
| Temperature | 65–70°F after sprouting |
| Spacing | Thin so leaves don’t shade each other |
| Rotation | Turn pots 1/4 turn daily |
Common Questions
Can leggy seedlings recover? Slightly leggy ones can. Severely leggy ones usually don’t.
Should I cut off the leggy stem? No. Bury it. Tomatoes and basil grow roots from buried stems.
Do I need a grow light? If your window gets less than 6 hours of direct sun, yes.
How close should the grow light be? 2–4 inches above the top leaves for most seedlings.
Why are only some of my seedlings leggy? Light is uneven.
Will leggy seedlings produce fruit? Usually not well. Better to restart.