Celery
Apium graveolens var. dulce
Also known asGarden celery · Pascal celery · Apio · Sellerie
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 3–10 (winter low around -40°C)
- Frost
- frost hardy
- Season
- cool (spring/fall)
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Perlite (Expanded volcanic glass) | neutral / inert | very low | low |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 2 | 1 | 1 | 1 |
| vegetative | 2 | 1 | 2 | 2 |
Companion-growing notes
- Heavy uptake of potassium, calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
- High transpiration. Regular reservoir top-ups needed during fruiting.
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
A notoriously finicky hydroponic crop that rewards careful moisture and temperature control. NFT, deep water culture or raft systems suit it, since constant water contact echoes its wetland origins. Hold EC around 1.8-2.4 mS/cm and pH 6.0-7.0. Temperature is critical at 15–22°C: celery bolts and turns bitter and tough above 25°C, and prolonged cold below 10°C can also trigger bolting. Keep light moderate, 14-20 mol/m2/day. It is a long crop, 80 to 150 days from transplant, and seed should be started indoors 10 to 12 weeks ahead since germination is slow. The stalks must grow quickly and without interruption to stay tender; any check from drought, heat, cold or nutrient shortage brings bitterness, stringiness and hollow stalks. Blanching the lower stalks reduces bitterness and pales them, though self-blanching varieties skip that step. Steady calcium and boron prevent blackheart, browning of the inner growing point. Celery is most practical as a fall or winter crop where cool temperatures come naturally.