Common seedling mistakes

Overwatering. Seedlings need damp, not wet. Roots breathe — saturate the medium and they suffocate. Water in small sips around the stem, not floods over the whole pot. Let the surface dry slightly between waterings.

Weak or too-far lighting. A 60–100W LED at 24–36 inches is plenty for early seedlings. Too dim and they stretch (long thin stem). Too close and the leaves curl/burn.

Premature feeding. Seedlings live off the seed's cotyledons for ~10–14 days. Feeding nutrients before they've used 3–4 true leaf sets just creates nutrient burn (yellowing/crisping leaf tips).

Buried too deep. Plant ~5–10mm deep; deeper and the seedling exhausts itself reaching daylight.

Damping off. Fungal pathogen that collapses seedling stems at soil level. Prevent with sterile medium, gentle airflow, and avoiding chronic moisture saturation.

Five seedling rescue scenarios

• Stretching seedling: lower the light by 6 inches, give the stem a gentle wiggle daily to stiffen it.
• Yellow cotyledons (round leaves): normal — they're meant to fade.
• Yellow true leaves: nutrient deficiency, but at seedling stage it's almost always pH or water stress, not feed.
• Curling new growth: heat stress — raise the light, drop temp.
• No growth for a week: usually overwatering. Let the medium dry out for 3+ days.