Vegetable · Brassicaceae
Rutabaga
Brassica napus subsp. rapifera
Start it in the warmth of summer, keep the soil company through the season, and let a hard frost turn the roots sweet for a harvest that stores for months.
Full sun
Every 3–7 days
41–77°F · 5–25°C
90–100 days
Overview
Rutabaga belongs to the cabbage family, and gardeners grow it for one thing above all: the dense golden root that swells up to the soil line. It most likely began long ago as a cross between a turnip and a wild cabbage, and it has quietly kept northern kitchens and winter livestock fed for centuries. You will also hear it called the swede or Swedish turnip, and it feels most at home where summers stay mild and autumn brings real cold.
If there is one thing rutabaga asks of you, it is a little patience. It wants a long, cool season of around 90 to 100 days, quite a bit more than a quick turnip, and it does its finest growing as the air cools toward fall. Once dug, those solid roots keep for months in a cool cellar, which is exactly why generations relied on them before there were refrigerators.
The good news for a first-timer is how little fuss it makes once planted. Give it deep, loose soil, water that stays even, and enough elbow room to fill out, and the weather handles the rest. A few hard freezes turn the root's starch into sugar, so the rutabaga you lift in late fall will taste far sweeter and kinder than one pulled in a hurry.
Care
The short version: give rutabaga full sun and deep, loose, well-drained soil, and water it enough to keep the roots from going woody, about an inch a week. Sow in the warmth of summer, thin the young plants to 8 inches apart, and wait to harvest in fall until a hard frost or two has passed.
Light
Rutabaga is happiest in full sun, which really just means about 6 or more hours of direct light each day. It will put up with a bit of partial shade if it must, though the roots take longer and stay smaller where the light is thin, so give it the brightest spot you can.
Water
Try to keep the soil evenly moist, roughly an inch of water a week, and pay closest attention while the roots are filling out. If the bed keeps swinging from bone dry to soaked, the roots can turn woody, cracked, and bitter, so steady is the goal, and it forgives the odd missed watering.
Soil
Set rutabaga into deep, loose, fertile loam that drains freely and holds plenty of organic matter, with the stones picked out so the root can push straight down. A pH between 6.0 to 7.0 suits it well, and keeping toward the higher end also helps hold clubroot at arm's length.
Temperature
This is a cool-weather crop, comfortable between 41°F and 77°F (5°C to 25°C), and it grows sweeter as the season slips toward cold. Real heat leaves the roots tough and sharp, while the frosts of fall are the gift that turns their starch to sugar.
Humidity
Ordinary outdoor air is all rutabaga needs, so there is no humidity number to fuss over. What counts far more is steady moisture in the soil and good airflow around the leaves, which keeps foliage diseases from settling in.
Feeding
About 3 to 4 weeks after planting, side-dress with a little nitrogen, such as calcium nitrate or a balanced fertilizer, to encourage strong leafy growth before the roots bulk up. If you worked compost into the bed beforehand, that groundwork carries much of the feeding for you.
Pruning
There is really no pruning to worry about with rutabaga. Just thin the seedlings to about 8 inches apart so each root has the room it needs to grow round and full, and pinch off any diseased leaves you happen to notice.
Size & spacing
In leaf, the plants stand about 12 to 18 inches (30 to 45 cm) tall, while the swollen root rests down at the soil line. Leave each one roughly 8 inches (20 cm) of space, and the roots will have plenty of room to grow generous and rounded.
When to plant
Think of rutabaga as a fall crop you get started while it is still warm out. Sow it any time from late spring through mid-summer, let it take the long cool stretch it needs to fill out, and hold off on digging until one or more hard frosts have sweetened the roots for you.
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
Most of what goes wrong with rutabaga happens quietly, down at the root or among the tender seedlings, so it helps to know the early warning signs up top. Catch them in time and you can usually step in before a soil pest or disease costs you the crop. Look through the trouble below, find the match, and act while it still makes a difference.
Brown tunnels bored through the root with wilting outer leaves
Those channels running through the flesh are the doing of the cabbage maggot, whose larvae burrow near the crown while the outer leaves start to droop. Lift any root that is already infested and destroy it rather than adding it to the compost. Going forward, lay a floating row cover over the bed right at sowing, and give brassicas a fresh patch of ground each year so the flies lose their foothold.
Fix:
- Remove and destroy infested roots
- Avoid planting brassicas in the same bed in successive years
Stunted plants with swollen, club-shaped roots
Distorted, swollen roots paired with wilting in the midday heat are the mark of clubroot, a soil-borne disease that can linger for years once it takes hold. There is no cure, so pull any infected plant and bin it rather than composting it. Keep your soil pH close to 7.0, work on drainage, and rotate well clear of cabbage-family crops to keep it from spreading.
Fix:
- Remove and destroy infected plants
- Do not compost infected material
Tiny shot-holes peppering the young leaves
When small round holes appear across the leaves, especially on little seedlings in warm, dry spells, that is flea beetle damage. Give the foliage a tap and you will spot the tiny black beetles springing away. Cover the seedlings with a row cover from the moment they emerge and keep them well watered, so they grow faster than the beetles can chew, and they usually pull through just fine.
Fix:
- Cover seedlings with row cover
- Keep plants well watered and vigorous to outgrow damage
A brown, watery core inside an otherwise sound root
If the outside looks fine but the center is grey-brown, corky, and bitter, you are looking at brown heart, which comes from a shortage of boron in the soil. Slice a root open to confirm the breakdown at the core. Have the soil tested before you add any boron, since too much turns toxic, and keep the watering steady, especially on lighter ground.
Fix:
- Apply boron-containing fertilizer only per a soil test
- Maintain even soil moisture
Toxicity
Rutabaga is food, plain and simple, and every part of it is safe to eat for people and animals alike. The roots and the leafy tops have been on plates and in feed troughs for generations, so there is really nothing to fear here beyond keeping any treat sensible in size.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Whether cooked or raw, rutabaga is perfectly safe for a cat, even if most cats can barely be bothered with it. A small nibble of root or leaf will do no harm at all.
Dogs None
A little plain rutabaga makes a fine treat for a dog, and plenty happily accept a cooked piece. Just keep the portions modest so the extra fiber does not unsettle a tender stomach.
Horses Safe
Rutabaga sits well with horses and causes them no trouble. Cut it into small chunks rather than handing over a whole root, which is far too easy to choke on.
Rabbits Safe
Both the root and the leafy tops are safe for rabbits as part of a mixed diet. Bring in any new vegetable a little at a time so the gut has a chance to settle.
Livestock Safe
Rutabaga has fed cattle and sheep through winter for a very long time, roots and tops together. Grazing hard on the raw brassica day after day can press on thyroid function through its natural goitrogens, so let it share the ration with other forage.
Birds Safe
Chickens and other backyard birds are glad to peck at both the root and the greens with no ill effect. Chop it into small pieces so it is easy for them to handle.
People Safe
For the cook, rutabaga is a wholesome and comforting vegetable, lovely roasted, mashed, or dropped into a stew. Both the roots and the young leaves are edible and safe on the plate.
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
You will only meet a few rutabaga varieties in most seed catalogs, and they have more in common than not. Still, these are the names worth remembering when you go looking for seed.
American Purple Top
This is the standard most gardeners grow, forming globe-shaped roots with purple shoulders above yellow flesh that warms to orange once it is cooked.
Laurentian
A dependable purple-top type prized for its fine-grained, sweet yellow flesh, which makes it a favorite to tuck away for fall storage.
Joan
An early, smooth-skinned purple-top that comes with a welcome bit of built-in tolerance to clubroot.
How to propagate
Rutabaga starts from seed, and only from seed, sown right in the spot where it will grow to size. It does not take kindly to being moved, so there is no clever shortcut worth chasing here.
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
Sow rutabaga right where it will grow, tucking the seed about a quarter to half an inch deep any time from late spring to mid-summer for a fall crop. The seedlings tend to appear within a week or two, and thinning them to roughly 8 inches apart gives each root the space to swell to full size over the following 90 to 100 days. Skip transplanting altogether, since rutabaga resents being moved and always does better sown in its final home.
Myths
Rutabaga and turnip are just two names for the same vegetable.
They are actually two different species that grow in their own ways. Rutabaga is the bigger, yellow-fleshed, sweeter root that needs a long cool season to do well, while the turnip is a quicker, smaller, white-fleshed crop you can pull within weeks of sowing.
Get rutabagas out of the ground before frost or they will spoil.
Frost is honestly the best thing that can happen to this crop. One or two hard freezes turn the root's starch into sugar, so the flavor gets better after frost, and the sweetest harvest waits until those cold nights have done their quiet work.