Stretching Seedlings? (Light Too Weak)
Leggy seedlings mean not enough light or too far away; stems thin and fall over.
Stretching seedlings? Light too weak—fix PPFD and analyze fast.
Common Causes
- Low PPFD/weak light
- Light too far
- High temps with no airflow
How to Tell Which One You Have
Tall thin stems leaning; cotyledons small; soil still moist.
FAQ
Fix?
Lower/increase light to target PPFD, add gentle airflow.
Bury stem on transplant?
Yes, when potting up.
Need nutrients?
Usually not; fix light first.