Rutabaga
Brassica napus var. napobrassica
Also known asSwede · Yellow turnip · Neeps (Scottish) · Kålrot · Steckrübe
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 2–8 (winter low around -46°C)
- Frost
- very hardy (survives deep cold)
- Season
- cool (spring/fall)
Growing systems
Root mass: heavy. Thin-channel systems can't hold this crop.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Soil-based mix (Potting soil) | varies | high | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
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 | 3 | 1.8 |
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 cool-season root crop for media beds or large containers (15 cm depth). EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 10–22°C (cool-season; above 25°C, roots become woody and bitter). Moderate light (DLI 14-20 mol/m2/day). From seed to harvest: 80-100 days (longer than turnips, which are 40-60 days). Direct seed or transplant into deep, loose media. Thin to 15–20 cm spacing (rutabaga roots grow large, 8–15 cm diameter). Harvest after the first frost if possible; frost-sweetened rutabaga is noticeably better than warm-weather-grown. For mashed rutabaga: peel, cube, boil until tender, mash with butter, salt, and white pepper. The flavor is sweeter and more complex than mashed potatoes. Boron deficiency causes brown, corky internal discoloration (brown heart); ensure the nutrient solution includes adequate boron. Cabbage root maggot is the main pest. Rutabaga stores for 3-6 months at 1–4°C with high humidity.
Notable varieties
| Cultivar | Type | Origin | Days | Notes |
|---|---|---|---|---|
| Laurentian | open pollinated | 105 | The standard North American rutabaga, yellow flesh, purple-topped, the variety most supermarket rutabagas are. | |
| American Purple Top | open pollinated | 100 | Similar to Laurentian, slightly earlier. Reliable garden variety. | |
| Joan | open pollinated | UK breeding program | 95 | Smooth-skinned, mild-flavored, the British supermarket swede. Earlier than American Purple Top. |