How to Grow Rutabaga

Woman harvesting rutabaga in vegetable garden
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Not many gardeners grow rutabagas. In truth, rutabagas have never really caught on in the U.S. Maybe that's because we're impatient, and most varieties of rutabagas take three to four months to mature, while their smaller cousin, the turnip, can be grown in half that time. More likely, though, it's because many of us have bad memories of rutabagas being overcooked into an unappetizing mush. But when grown and prepared properly, rutabagas have a peppery cabbage flavor that sweetens as it cooks.

Rutabagas are in the mustard family and are a cross between turnips and cabbage. Since they grow well in cool weather and can be harvested into winter, they tend to be popular in northern countries. Another name for them is Swedish turnips or swedes.

Rutabagas are large oval or slightly elongated bulbs with firm yellow flesh. The leaves of rutabaga plants, which are edible, are similar to turnip leaves but are thicker, like cabbage or kale leaves. Rutabagas often do not flower, but when they do, it is a small, yellow Brassica flower, with four petals that form a cross and give them their designation as cruciferous vegetables. They are typically planted in spring, but they can be planted in fall in warm climates.

Botanical Name  Brassica napus (Napobrassica Group)
Common Name  Rutabaga, Swedish turnip, swede 
Plant Type  Root vegetable 
Mature Size  12 to 24 inches tall, 9 to 12 inches wide 
Sun Exposure  Full sun 
Soil Type  Loamy, well-drained 
Soil pH  Slightly acidic to neutral (6.0 to 6.5) 
Bloom Time  Rarely flowers 
Flower Color  Yellow 
Hardiness Zones  3 to 9 
Native Area  Europe 

How to Plant Rutabagas

Rutabagas are biennials grown as an annual crop. They may go to seed in their first year if they are planted early in the spring. In cooler climates, rutabagas are direct seeded in late spring, after the danger of frost, so that they will mature in the fall. In warm climates, they are usually seeded in the fall and grown over winter. They will not sweeten if they mature during hot weather.

Plant the seeds about 1/2 inch deep. Thin the seedlings when they are about 3 to 4 inches tall, so the bulbs will have room to fill out. You can toss the thinned greens into a salad or stir-fry.

Rutabaga Care

Light

Rutabagas do best in full sun, which means about 6 hours of direct exposure per day. They will tolerate partial shade.

Soil

Rutabagas prefer a slightly acidic soil pH in the range of 6.0 to 6.5. Good soil fertility will help them grow throughout their long season; amend the soil before planting if it is poor. Most importantly, make sure the soil is well-draining so the bulbs don't rot.

Water

Proper watering is vital for good root development. Give your rutabagas at least 1 inch of water per week; give them more during particularly hot, dry weather.

Temperature and Humidity

Rutabagas grow well in a range of temperature and humidity conditions. In dry areas, they are prone to cracking and will not develop their sweetness if they're not given enough water. Rutabagas are sweetened by a little frost. You can harvest them in the fall (or late winter in warmer climates) or you can leave them in the ground with a thick layer of straw mulch and harvest as needed.

Fertilizer

If you start with soil that is rich in organic matter, you won't need any additional fertilizer. A side dressing of compost, applied mid-season, will give your plants the boost they'll need to get through to fall.

Rutabaga Varieties

  • Altasweet: Mild, less peppery flavor; matures in 90 to 100 days
  • American Purple Top: Popularly grown variety with large bulbs; matures in 90 to 100 days
  • Laurentian: Heirloom variety with uniform, sweet bulbs; matures in 90 to 120 days
  • Pike: Similar to ‛Laurentian' but a little hardier; matures in 100 to 120 days

Harvesting Rutabagas

Rutabaga plants grow about 12 to 24 inches tall and 9 to 12 inches wide. The bulbs can become the size of a softball, or larger. That's often what you find in the grocery store. However, they are best when harvested smaller, at 3 to 5 inches in diameter. Larger bulbs tend to get tough. The greens can be harvested any time after they reach 4 inches tall. If you don't harm the top of the bulb, the greens will continue to regrow.

Although rutabagas are related to turnips, they have a different flavor altogether. Rutabagas are sweeter and almost buttery when cooked. You can use them for baked dishes, like casseroles, soufflés, and even pies. They are also excellent as a side dish when mashed or baked like fries. And, of course, they are wonderful roasted and are great in soup.

Raw rutabagas are crunchy and juicy. You can slice, cube, or grate ​them into all kinds of dishes and snacks. The bulbs can be stored in the refrigerator or any cool, dark place for months. Just be sure to remove the leaves before storing the bulbs.

Common Pests and Diseases

There are several insects, such as flea beetles, that will chew on and damage the leaves of rutabagas. If you plan to use the greens, a row cover will protect them. Root maggots cause more of a problem because they damage the bulbs. The row covers will help with these, as well, by preventing the moths from laying their eggs on the leaves.

Rutabagas are less susceptible to disease than many other Brassica plants, but you should still rotate your crops to help prevent problems. The main disease that ruins crops is clubroot. If your plants get clubroot, it is recommended that you wait six years before grow any Brassica plants in the same area again.