5 Tips for Growing Plump, Sweet Rutabagas

With a flavor that's both earthy and subtly sweet, rutabagas are as versatile in the kitchen as they are resilient in the garden. Gardener Lindsay Miller shares 5 quick tips for keeping these keeper crops plump and sweet.

Written by Lindsay Miller Horticulture review by Sarah Jay Last updated: October 14, 2024 | 3 min read

The Rutabagas roots, displayed in a wooden box, are globe-shaped with a firm, waxy skin that showcases a rich purple color at the top, fading to a light yellow near the base.

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Rutabagas are often confused with their slightly more popular cousin, the turnip, although the latter are typically smaller in size and spicier in flavor. Growers didn’t do this hardy root any favors in naming it either: Rutabaga is derived from the Swedish word “rotabagge”, which means “baggy root”. Despite their unflattering name and relatively unphotogenic appearance (hard to compete with a bold, gorgeous tomato), rutabagas are an easy addition to the veggie garden.

Rutabagas (Brassica napus var. napobrassica) have large, softball-sized roots that are usually golden yellow to purple-brown in color. This unassuming root is chock full of fiber, potassium, vitamin C, and calcium. They can be prepared in a myriad of ways, including roasted, sautéed, baked, fried, boiled, and mashed. They have a mild, sweet-meets-earthy flavor that pairs well with a host of other ingredients.

That sweet flavor is the result of careful calendar planning. This crop requires a long growing season and taste its best when allowed to mature during the coolest weeks of the season. Sowing these seeds at the right time is important! Read on and learn more tips to guarantee sweet, plump rutabagas this season.

Time Your Seeds Right

Garden bed with growing plants showcasing broad, green leaves with wavy edges, emerging from sturdy stems that support round, bulbous roots, which are purple on the top and creamy yellow underneath. — Cool, moist soils yield the sweetest root vegetables.

Like their fellow root veggie cousins, turnips, rutabagas prefer cool, moist soils. However, unlike turnips, which can be planted in either early spring or early fall, rutabaga seeds should be planted in mid to late summer.

This is because they take much longer to grow (90-100 days versus 45-60 for turnips), and their roots need to mature during cool weather for the sweetest flavor. Rutabagas grown out during hot weather tend to be tough, woody, and flavorless.

Feed Your Soil First

The gardener's hands hold a handful of fresh compost mixed with dark, loose soil, set against the backdrop of a garden bed. — Support healthy growth with well-drained soil and balanced nutrients.

Rutabagas are quite forgiving in terms of soil as long as it’s well-drained. Loosen heavy clay soils by digging in a healthy application of compost at the beginning of the garden season. If you have especially stubborn, waterlogged soil, consider growing this crop in a raised bed. Unlike most brassicas, these do not require overly rich, nitrogen-heavy soils. They grow best in soil that’s neutral to slightly acidic, with a pH range of 6.2-7.0.

However, rutabagas are sensitive to boron deficiency. Boron is a micronutrient that is required in very small amounts by other veggie crops. Still, most brassicas, including rutabagas, broccoli, turnips, and beets, have relatively high boron requirements.

Boron deficiency can cause the crop to develop soft brown centers, a disorder called “brown heart”. Amend boron-deficient soils with plenty of finished compost or agricultural borax.

Prevent Disease

The plant features large, sprawling leaves showing signs of disease with brown-black spots, growing from sturdy stems that support its bulbous roots, which have smooth skin in shades of purple and pale yellow. — Protect your crops to prevent diseases and ensure sweetness.

While largely resilient, these brassicas are susceptible to several diseases that can quickly zap their normally plump, sweet roots. Clubroot is a soil-borne disease that infects rutabaga roots, causing them to swell. Infected roots cannot absorb water or nutrients. Clubroot is difficult to eradicate from the soil. Remove and dispose of all infected plant material in the trash; don’t attempt to compost them. Club-root infected soil should not be used to grow any plants in the brassica family for at least five to seven years.

The fungus-derived alternaria leaf spot can also damage them. Dark brown leaf spots with yellow halos are typically the first sign of alternaria leaf spot infection. Infected rutabagas do not store well because weak spots allow for other rots and molds to set on the roots.

Unfortunately, rutabagas thrive in the same conditions that can give rise to fungal infections: cool temperatures and long periods of high humidity. Treat alternaria leaf spot-infected plants with a copper-based fungicide. Prevent this disease by rotating your brassica crops, irrigating the soil directly without dampening the aboveground foliage, and planting certified disease-free seeds.

Provide Plenty of Water

Close-up of a watered plant showcasing large, globe-shaped roots and strong green leaves with deeply lobed, slightly hairy surfaces, emerging from thick stems adorned with drops of water. — Consistent moisture is key for sweet, tender roots.

Despite being essentially one giant storage root, this vegetable is not drought-tolerant. Rutabagas love plenty of moisture, and prolonged droughts can make roots taste bitter and split. Aim to provide 1-2 inches of water every 7-10 days.

Consistent, regular watering is especially important as you approach harvest and the root nears maturity. Gardeners in particularly hot or arid climates may want to set up a soaker hose or drip irrigation system to ensure their roots get plenty to drink.

Wait For a Frost (or Two)

The matured plant appears with its robust, bulbous roots partially buried under a blanket of snow, while its sturdy green leaves peek out, coated in snow. — Frost enhances flavor, so wait before pulling roots.

It’s been said that frost improves the flavor of this root, so wait for at least one hard frost before harvesting. For some cold-climate gardeners, this could be as early as late September, although for many of us, this will mean waiting until October, November, or even as late as December. Hard frosts may damage rutabaga greens, but the roots can survive these periods. As long as the ground isn’t frozen solid, leaving them in the garden is safe.

Harvest rutabagas when the roots are roughly 3-5 inches in diameter. Gently loosen the surrounding soil with a broadfork and then pull up the entire plant like you would a turnip. Avoid damaging the root if you plan to store it for an extended period of time, as punctures in the skin can invite mold and bacteria.

Store rutabagas at 32-40°F (0-4°C) and 95% relative humidity. Low humidity will dry the roots out and give them an unpleasant, woody texture. This is a great keeper crop that will remain plump and sweet for several months if stored properly!

Key Takeaways

Rutabagas are a low-maintenance and easy addition to the veggie garden. Guarantee big, healthy harvests by sowing this plant at the right time of year, providing plenty of water, and waiting for a frost before pulling up those roots.

Remember, patience is key—these hardy root veggies take their time to reach perfection, but the sweet, earthy reward is well worth the effort. Enjoy every bite of your homegrown baggy roots!