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 1.4-2.0 mS/cm. pH 6.0-7.0. Temperature: 10–22°C (cool-season; above 25°C roots turn woody and bitter). Moderate light (DLI 14-22 mol/m2/day). From seed to harvest: 90-120 days (longer than turnips, which take 40-60). Direct seed or transplant into deep, loose media and thin to 15–20 cm spacing, since the roots grow large (8–15 cm across). Harvest after the first frost where possible, as frost-sweetened rutabaga is noticeably better than warm-grown. For mashed rutabaga, peel, cube, boil until tender and mash with butter, salt and white pepper for a sweeter, more complex result than mashed potato. Boron deficiency causes brown, corky internal discoloration (brown heart), so keep boron adequate in the nutrient solution. Cabbage root maggot is the main pest, and rutabaga stores 3-6 months at 1–4°C in 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. |