Swiss chard
Beta vulgaris subsp. cicla
Also known asSilverbeet · Chard · Spinach beet · Seakale beet · Perpetual spinach · Mangold · Acelga · Bette à carde
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 5–10 (winter low around -29°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 |
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Net pot, no medium (Bare-root) | - | - | - |
| 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 | 1 | 1 | 1 | 0.8 |
| vegetative | 3 | 1 | 2 | 2 |
Companion-growing notes
- Heavy uptake of calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
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
One of the easiest and most productive hydroponic leafy greens, with the bonus of dramatic visual appeal from the colorful stalks. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 12–28°C (wider tolerance than spinach; produces through summer and mild winters). Moderate light (DLI 14-20 mol/m2/day). Any hydroponic system works (NFT, DWC, media beds). From transplant to first harvest: 5-7 weeks. Harvest outer leaves (cut-and-come-again) while the center continues producing new leaves. A single plant provides harvests every 1-2 weeks for 3-6 months, making chard one of the longest-producing individual plants in any hydroponic system. 'Rainbow' or 'Bright Lights' chard adds color that sells at farmers' markets ($4-8/bunch). The colorful stalks are excellent pickled: quick-pickle with vinegar, sugar, and spices for a stunning, flavorful condiment.