How to Grow Rutabaga

Rutabaga growing in the ground

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Rutabaga (Brassica napobrassica), is a root vegetable that's believed to have originated as a cross between the cabbage and the turnip. Rutabagas might not be as popular as their smaller and faster-growing turnip cousins, but they're still easy to grow and full of flavor.

The leaves of rutabaga look similar to a turnip, but they're thicker and almost kale-like. They produce the typical small and yellow Brassica flower with four crossing petals that resemble a crucifix—identifying them as cruciferous vegetables. Rutabagas have beautiful pale gold oval bulbs with a purple crown and a peppery, cabbage-like flavor. They're sweeter and more buttery than turnips, and the greens are also delicious.

Rutabaga bulbs can grow to be at least the size of a softball, but they retain their best flavor when harvested smaller. They grow well in cool weather and can be harvested well into the winter, making them a popular choice in northern regions. Rutabagas taste delicious when roasted, added to soups, or baked in casseroles, soufflés, and even pies. Crunchy and juicy, it's also possible to chop them up and eat them raw.

Rutabaga can be planted from seed in early spring for summer harvest but is more often planted in early summer for fall harvest. Seeds take about four months (considerably longer than turnips) to mature into harvest size.

Botanical Name Brassica napobrassica
Common Name Rutabaga, Swede, yellow turnip
Plant Type Root vegetable
Mature Size 1–2 ft. tall, 9–12 inches wide
Sun Exposure Full sun
Soil Type Loamy, well-drained soil
Soil pH 6.0 to 6.5 (slightly acidic)
Hardiness Zones 3 - 9 (USDA)
Native Area Europe

How to Plant Rutabaga

Because rutabaga takes up to four months to fully mature and requires cool temperatures during the late maturation process, they are often planted fairly late to take advantage of cool early fall temperatures. It's common to plant rutabagas about 100 days before the first fall frost, which in some regions means that late June or even July is the ideal planting date.

Sow rutabaga in rows 18 to 24 inches apart; thin the seedlings to a spacing of 6 inches when they have several sets of true leaves.

Plant Care

Light

Rutabaga do best in a full sun location, but they can still grow in part shade.

Soil

Rutabagas prefer a slightly acidic soil pH in the range of 6.0 to 6.5. As with all root vegetables, good soil fertility will help them grow throughout their long season. Adding organic matter to less fertile soil is recommended. And make sure the soil is well-draining, so the bulbs don't rot.

Water

At least 1 inch of water per week is vital for good root development—more during particularly hot, dry weather. Rutabagas that grow in dry conditions are prone to cracking and won't develop their sweetness.

Temperature and Humidity

A little frost sweetens rutabagas. You can dig 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, mid-season, will give rutabagas the boost they'll need to get through to fall.

Be aware that too much nitrogen can result in deformed bulbs, so if you're using fertilizer, double-check the balance before mixing it with the soil.

Rutabaga Varieties

  • 'Altasweet': This variety has a mild flavor that isn't as peppery as some.
  • 'American purple top': This is a popular variety with large bulbs that have a deeper purple crown.
  • 'Laurentian': This variety has sweet bulbs and a uniform shape. It shares similarities with the American purple top but tends to have a smaller root.
  • 'Pike': -Similar to ‛Laurentian, pike is known to be a little hardier, and it takes a little longer to mature.

How to Grow Rutabaga From Seed

In cooler climates, rutabagas are direct-seeded about 1/2 inch deep, generally about 100 days before the first fall frost. Depending on your region, this can mean a relatively late planting date, well after most other vegetables are in the ground. In warm climates, rutabagas are usually seeded in the fall and grown over winter. They won't sweeten if they mature during hot weather.

Plants will need to be thinned when they're about 3 to 4 inches tall, so the bulbs will have room to fill out. If they're crowded, it can result in overly large tops and straggly roots.

Harvesting Rutabaga

Rutabaga 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.

Rutabaga tubers are ready to harvest when they are 3 to 5 inches in diameter, and will be better-tasting at this point before they get too large. Larger bulbs tend to get tough. But you can also allow them to remain in the ground after the early frost because cool temperatures simply make them sweeter.

Common Pests and Diseases

Rutabagas are less bothered by pests than most Brassica plants, but you should still rotate your crops around the garden. The main disease that ruins rutabaga is the soil-borne fungus clubroot. If your plants get clubroot, it's recommended you wait six to ten years to grow any other Brassica plants in that area.

There are several insects, such as flea beetles, that will chew on and damage the leaves of rutabaga. If you plan to use the greens, a row cover will protect them. Root maggots are more problematic 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.