How to grow Spinach hydroponically
Spinacia oleracea reaches harvest in 16 days in a hydroponic system, with a preferred pH of 5.6–6. This guide compiles the operating parameters published by university extension sources for this crop.
Target pH
Maintain reservoir pH at 5.6–6. pH controls how readily the roots can absorb each nutrient; outside this window the plant shows symptoms of deficiency even when the nutrients are physically present in solution.
Measure with a calibrated pH meter at the same time each day and log the reading. Drift of more than 0.3 units over 24 hours usually signals a reservoir change or a nutrient imbalance.
Nutrient schedule
Targets in ppm for the elemental nutrients most commonly tracked in home hydroponics. EC is shown per stage where the cited source publishes it; absence of a stage EC is intentional and not a data gap.
| Stage | EC (mS/cm) | N (ppm) | P (ppm) | K (ppm) |
|---|---|---|---|---|
| vegetative | 1.3 | 125 | 31 | 215 |
Lighting
Daily Light Integral: 17–22 mol/m²/day. Multiply your fixture’s PPFD by photoperiod hours by 0.0036 to compare against this target.
Photoperiod: 14 hours per day — general practice, plant-specific guidance not published.
Compatible systems
Hydroponic methods that have been documented as workable for this crop in the cited literature.
- Deep Water Culture (DWC)
- Nutrient Film Technique (NFT)
- Floating Raft
Common problems
- root rot
- Likely cause: pythium aphanidermatum in warm water. Fix: hold water at 15 to 20c and use a two pond system.
Sources
All numeric parameters on this page are drawn from the following extension and research sources.
- Cornell CEA Hydroponic Spinach Production Handbook (Brechner & de Villiers, 2013) (accessed 2026-05-30)