How Much Light Does Spinach Need? PPFD & DLI
Cool-season leafy green. Cornell's hydroponic protocol gives baby spinach about 17 mol/m²/d of light and harvests it 14 days after sowing. Heat and long days make it bolt.
- Peak PPFD: 300–345 µmol/m²/s
- Peak DLI: 17–20 mol/m²/d
- Air temperature: 16–22 °C
- Relative humidity: 50–70 %
- VPD target: 0.7–1 kPa
- Do not leave the substrate dry for more than 2 days
Targets per growth stage
| Stage | From day | PPFD | DLI | Photoperiod | pH | EC |
|---|---|---|---|---|---|---|
| Seedling | 0 | 50–150 µmol/m²/s | 3–9 mol/m²/d | 16 h | 5.6–6 | 1.2–1.4 |
| Growth | 2 | 300–345 µmol/m²/s | 17–20 mol/m²/d | 16 h | 5.6–6 | 1.2–1.4 |
| Mature | 14 | 300–345 µmol/m²/s | 17–20 mol/m²/d | 16 h | 5.6–6 | 1.2–1.4 |
Watering
Keep the substrate evenly moist; spinach wilts quickly and roots rot in warm, stagnant water.