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 attention to moisture and temperature. NFT, DWC, or raft systems suit celery well because the constant water contact mimics its wetland origins. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 15–22°C (critical: celery bolts in heat above 25°C and produces bitter, tough stalks; below 10°C for extended periods can also trigger bolting). Moderate light (DLI 12-18 mol/m2/day). Long crop: 80-100 days from transplant. Start seeds indoors 10-12 weeks before transplant (germination is slow, 2-3 weeks). The stalks must grow quickly and continuously to be tender and mild; any check in growth (drought, heat, cold, nutrient deficiency) causes bitterness, stringiness, and hollow stalks. Blanching (wrapping the lower stalks in cardboard or growing in opaque tubes) reduces bitterness and produces paler stalks, but self-blanching varieties ('Golden Spartan', 'Tango') eliminate this step. Calcium and boron supplementation prevents blackheart (internal browning of the growing point). For hydroponic growers, celery is most practical as a fall/winter crop where cool temperatures are naturally available.