Vegetable · Brassicaceae
Rutabaga
Brassica napus subsp. rapifera
Beneath a leafy crown sits the heavy rutabaga, purple across its shoulders and golden-yellow through its dense flesh, sweetening after a hard frost.
Full sun
Every 3–7 days
41–77°F · 5–25°C
90–100 days
Overview
Rutabaga is a cool-season root in the cabbage family, and its signature is the heavy, rounded root that swells right at the soil line, its crown often shouldered in dull purple above pale yellow flesh. The plant most likely came from a turnip crossed with a wild cabbage, and it has fed northern kitchens and winter livestock for centuries. It goes by the name swede or Swedish turnip as well, and it forms its best roots where summers stay mild and fall turns cold.
The root itself is what rewards the wait. Over a long, cool season of around 90 to 100 days, far more than a quick turnip needs, that globe fills out into a solid, close-grained mass of yellow flesh. Lifted and stored in a cool cellar, the dense root holds firm for months, which is how it served as a staple long before refrigeration.
Cut one open and the inside tells the story. The flesh is firm and yellow through and through, and after a few hard freezes turn the starch to sugar, that same flesh tastes markedly sweeter than a root pulled early. Set it on the stove and the pale yellow warms toward orange, the color deepening as it cooks.
Care
The short version: rutabaga wants full sun and deep, loose, well-drained soil, with about an inch of water a week to keep the round root from turning woody. Sow in summer, thin the seedlings to 8 inches apart, and lift the roots in fall after a hard frost or two.
Light
Rutabaga colors and sizes best in full sun, about 6 or more hours of direct light a day, which drives the root to fill out fully. Under a little partial shade it still grows, but the root swells more slowly and stays a smaller, less developed globe.
Water
Give the soil even, steady moisture, about an inch of water a week, most of all as the round root is swelling. Let it dry out and flood in turns and the flesh turns woody and cracked, its surface split and its taste gone bitter, rather than smooth and sweet.
Soil
Rutabaga needs deep, loose, fertile loam that drains freely and holds organic matter, cleared of stones so the swelling root can push straight down without forking. A pH of 6.0 to 7.0 suits it, and the upper end also helps hold clubroot, which knots the roots, in check.
Temperature
This is cool-weather flesh, at its firmest and sweetest between 41°F and 77°F (5°C to 25°C). Heat leaves the root tough and sharp-tasting, while the frosts of fall work through the flesh and turn its starch to sugar.
Humidity
Plain outdoor air suits rutabaga, so there is no level to reach for. What tells on the plant is steady soil moisture and open airflow through the leafy tops, which keeps the foliage clear of spotting disease.
Feeding
A side-dressing of nitrogen, whether calcium nitrate or a balanced fertilizer, about 3 to 4 weeks after planting pushes the leafy tops out ahead of the swelling root. Where compost is dug in first, that dark, crumbly soil carries much of the feeding on its own.
Pruning
There is nothing to prune on a rutabaga. Simply thin the seedlings to about 8 inches apart so each round root has bare soil to swell into, and strip away any leaf that shows disease.
Size & spacing
The leafy tops stand about 12 to 18 inches (30 to 45 cm) tall, with the swollen root breaking the surface at the soil line below them. Left roughly 8 inches (20 cm) of room apiece, the roots round out full and heavy rather than small and pinched.
When to plant
Rutabaga takes shape across two seasons, sown into warm summer soil and swelling into the cold. Direct sow from late spring through mid-summer, let the root fill out over the long cool weeks, and lift it only after one or more hard frosts have sweetened the flesh.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Direct sow in late spring to early summer (late May to early June in northern gardens; mid-summer to early fall in the South) for a fall harvest
- Harvest: Harvest in fall after one or more hard frosts, which sweetens the roots
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
The clearest signs of rutabaga trouble show on the plant itself, in the holes chewed through a leaf, the tunnels scored into the flesh, or the swellings knotting the roots. Reading those marks up close tells you what has taken hold before it spreads. Match the look of the damage below, then act while it still helps.
Brown tunnels boring through the root with wilting outer leaves
Slice into the crown and you find the tracks of the cabbage maggot: slender white larvae and the brown channels they bore through the pale flesh, while the outer leaves wilt above. Lift and destroy any tunneled root rather than composting it. A floating row cover laid over the bed at sowing, plus fresh ground for brassicas each year, keeps the egg-laying flies off.
Fix:
- Remove and destroy infested roots
- Avoid planting brassicas in the same bed in successive years
Stunted plants with swollen, club-shaped roots
A stunted plant that wilts in the midday heat, its roots knotted into swollen, club-shaped lumps, is showing clubroot, a soil-borne disease that stays in the ground for years. Nothing reverses the galling, so lift the misshapen roots and discard them rather than composting. Hold the soil pH near 7.0, open up the drainage, and rotate well clear of cabbage-family crops.
Fix:
- Remove and destroy infected plants
- Do not compost infected material
Small round shot-holes across the young leaves
A scatter of tiny round holes punched clean through the young leaves is the sign of the flea beetle, worst on seedlings in warm, dry spells. Tap the foliage and the specks that spring away are the small black beetles themselves. Cover the seedlings the day they break the soil and keep them watered, so the leaves push out faster than the beetles can pit them.
Fix:
- Cover seedlings with row cover
- Keep plants well watered and vigorous to outgrow damage
Brown, watery core within an otherwise sound root
A root that looks smooth and whole outside can hide brown heart within, a grey-brown, corky or watery core that tastes bitter, caused by a shortage of boron. Cut the root through and the breakdown shows at the center while the skin stays sound. Test the soil before adding any boron, which turns toxic in excess, and keep the moisture even on lighter ground.
Fix:
- Apply boron-containing fertilizer only per a soil test
- Maintain even soil moisture
Toxicity
Rutabaga is a food plant from root to leaf, and every part of it is safe for people and animals. The firm yellow root and the leafy green tops have both been eaten and fed to livestock for generations, so nothing here calls for worry beyond ordinary moderation.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
The firm root and its leaves are safe for cats whether cooked or raw, though most sniff and walk away. A small nibble of either does no harm.
Dogs None
A cooked piece of the yellow root makes a safe treat for a dog, and many take to it. Keep the portion small, since the extra fiber can unsettle a sensitive stomach.
Horses Safe
Horses eat rutabaga without trouble. Cut the heavy root into small chunks rather than offering it whole, since a whole globe is easy to choke on.
Rabbits Safe
Both the root and the leafy green tops are safe for rabbits within a varied diet. Introduce any new vegetable slowly so the gut can adjust.
Livestock Safe
Rutabaga has long been winter feed for cattle and sheep, the heavy roots and the leafy tops together. Grazing hard on the raw brassica day after day can press on thyroid function through its natural goitrogens, so it is balanced with other forage.
Birds Safe
Chickens and other backyard birds peck readily at the yellow flesh and the greens with no ill effect. Chop it small so they can manage the firm root.
People Safe
On the plate, rutabaga is a wholesome vegetable, the dense yellow flesh good roasted, mashed, or dropped into a stew. Both the roots and the young leaves are edible and safe to eat.
Like other brassicas, rutabaga contains glucosinolate goitrogens; very large raw quantities may affect thyroid function, so it is best fed in moderation and cooked.
Varieties
Only a few rutabaga varieties fill the seed catalogs, and they differ in small, visible ways, in the cast of the skin and the grain of the flesh. These are the ones worth knowing by sight.
American Purple Top
The most widely grown standard, its globe-shaped roots capped with purple shoulders over yellow flesh that deepens to orange once cooked.
Laurentian
A uniform purple-top whose close, fine-grained yellow flesh is sweet and firm, which is why it keeps so well in fall storage.
Joan
An early purple-top with notably smooth skin, and a useful measure of tolerance to clubroot.
How to propagate
Rutabaga grows from seed alone, sown right where the root will swell. Its taproot resents any disturbance, so it is left in place from the start rather than lifted and moved.
SeedEasy
Direct sow outdoors in late spring to mid-summer for a fall crop · Seedlings emerge in 1 to 2 weeks; roots mature in about 90 to 100 days
Set rutabaga seed straight into the ground where the root will swell, about a quarter to half an inch deep, from late spring to mid-summer for a fall crop. The seedlings break the soil within a week or two, and thinning them to roughly 8 inches apart leaves each round root bare space to fill out over the next 90 to 100 days. Do not lift and move the seedlings, since the taproot resents disturbance and the plant sizes up better sown where it stands.
Myths
Rutabaga and turnip are the same vegetable.
They are two distinct species, and it shows in the root. Rutabaga is the larger, yellow-fleshed, sweeter root that fills out over a long cool season, while the turnip stays smaller and white-fleshed and is pulled within weeks.
Rutabagas should be dug before frost or they spoil.
Frost changes the flesh for the better, not the worse. One or two hard freezes turn the starch inside the root to sugar, so the flesh grows sweeter after frost, and the best-tasting roots wait until the cold nights have passed.