How Much Light Does Tomato Need? PPFD & DLI
Demands high light during flowering and deep, regular watering.
- Peak PPFD: 350–950 µmol/m²/s
- Peak DLI: 20–55 mol/m²/d
- Air temperature: 22–28 °C
- Relative humidity: 50–70 %
- VPD target: 0.8–1.2 kPa
- Do not leave the substrate dry for more than 4 days
Targets per growth stage
| Stage | From day | PPFD | DLI | Photoperiod | pH | EC |
|---|---|---|---|---|---|---|
| Seedling | 0 | 265–345 µmol/m²/s | 15–20 mol/m²/d | 16 h | 5.8–6.3 | 0.8–1.2 |
| Vegetative | 14 | 400–600 µmol/m²/s | 23–35 mol/m²/d | 16 h | 5.8–6.3 | 2–3 |
| Flowering/fruiting | 42 | 350–950 µmol/m²/s | 20–55 mol/m²/d | 16 h | 5.8–6.5 | 3–4 |
Watering
Water thoroughly, but allow the topsoil to dry slightly between waterings.
Sources
- Wuetcher, L.T. & Owen, W.G. (2025). Managing DLI to Improve Vegetable Transplant Quality. e-GRO Alert 10(1), The Ohio State University — Supports: seedling light
- Stallknecht, E. (2025). Calculating and Using Daily Light Integral (DLI): An Introductory Guide. Virginia Cooperative Extension, SPES-720NP — Supports: light in production
Values not covered by a source above are common growing practice, not taken from a primary source.