Kale
Brassica oleracea var. sabellica
Also known asCurly kale · Lacinato · Borecole · Dinosaur kale · Tuscan kale · Cavolo nero · Sukuma wiki
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 3–9 (winter low around -40°C)
- Frost
- very hardy (survives deep cold)
- 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 | 1.6 |
Companion-growing notes
- Heavy uptake of nitrogen. 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
An easy, productive hydroponic leafy green for cool to moderate conditions. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 10–24°C (cool-season; tolerates heat better than most brassicas but flavor and texture are best in cool weather). Moderate light (DLI 14-20 mol/m2/day). NFT, DWC, media beds, or vertical towers. From transplant to first harvest: 5-7 weeks. Harvest by removing lower leaves (cut-and-come-again), leaving the growing tip and upper leaves to continue producing. A single plant provides harvests every 1-2 weeks for months. Lacinato (dinosaur) kale is preferred by many growers for its flavor (sweeter, less bitter than curly types) and ease of preparation (the flat leaves don't trap dirt and sand like curly kale). 'Red Russian' kale adds color to salad mixes and is tender enough to eat raw. Caterpillars (cabbage loopers, imported cabbageworm) and aphids are common pests; BT spray controls caterpillars. Kale is one of the most reliable, long-producing, and nutritious crops for any hydroponic system.
Notable varieties
| Cultivar | Type | Days | Notes |
|---|---|---|---|
| Lacinato (Dinosaur) | heirloom | 60 | Italian Tuscan heirloom, also Cavolo Nero or "Black Tuscan". Long narrow dark blue-green strap leaves, bumpy texture. Less curly than Vates, easier to chew raw. Cold-hardy to about -10C; sweetens after frost. |
| Red Russian | open pollinated | 55 | Russian heirloom with flat oak-leaf-shaped foliage, purple veins, frilled edges. Tenderest texture of common kales. Less cold-hardy than Lacinato (about -7C) but recovers faster after winter. |
| Curly Vates | open pollinated | 55 | Tightly curled blue-green leaves. The supermarket-bunch kale most US growers know. Productive over a long cut-and-come-again season. Most cold-hardy of the common kales, down to -15C with snow cover. |
| Redbor | hybrid | 55 | F1 with intensely curled deep purple leaves. Bred for ornamental use as much as eating; common in winter container plantings. Edible and pleasant; deeper purple after cold exposure. |