Growing Rutabagas for a Bumper Fall Harvest

19 July 2018, written by Barbara Pleasant

The most stalwart members of the turnip tribe, rutabagas are a rustic cross between wild turnip and cultivated cabbage that came about in Scandinavia, Russia or perhaps Lithuania in the late Middle Ages. The root word, rotabagge, is Swedish for thick root, which hints at the density of rutabaga roots when compared to turnips. Other names for rutabaga (Brassica napus var. napobrassica) include swedes, winter turnips, yellow turnips, Swedish turnips, Russian turnips, Canadian turnips, and neeps. By any name, they are a top storage crop to grow in the fall garden.

Midsummer is the best time to plant rutabagas, which need 10 to 12 weeks of growing time before the first fall frost. I like to sidestep hot summer sun by starting the seedlings indoors and setting them out when it’s cloudy, but the seeds are such willing germinators that they also can be direct-sown into a prepared row and thinned to proper spacing.

Avoiding Problems When Growing Rutabagas

Like most other root crops, rutabagas need sunny, well-drained soil with a near-neutral pH amended with a modest supply of organic fertilizer or composted manure. Too much nitrogen can lead to poor bulb formation, so it is best to use only half as much as the product’s label suggests when preparing the bed, with the other half applied a few weeks later, after the plants have been thinned and weeded.

Rutabagas are highly sensitive to boron deficiency, which leads to a condition called brown heart, a discolored hollow in the middle of the rutabaga. Supplemental boron is easily supplied with a light sprinkling of household borax into the planting row, or you can mix borax with water and douse the planting once, while the rutabagas are young. A little goes a long way, so allow only three pinches per plant. See my Miraculous Micronutrients article for more information on using boron in the vegetable garden.

Spacing is important, too, because crowded rutabagas will grow huge tops with skinny roots. Transplant or thin rutabagas to at least 8 inches (20cm) apart, with wider spacing even better. The largest rutabaga I’ve ever grown got mixed up with the Brussels sprouts and enjoyed plenty of elbow room.

“Thinning — Thin direct-sown rutabagas gradually to at least 8 inches (20cm) apart.

The same pests that bother other brassicas can affect rutabagas, but they usually don’t. Pests tend to leave rutabagas alone when more tender cabbage or kale are present, in part because rutabaga leaves are studded with prickly hairs. Should insects become an issue, you can always cover the plants with a barrier of tulle or another lightweight row cover.

Harvesting and Storing Rutabagas

Rutabagas make rapid growth once they become established, producing a profusion of leaves that show the plants’ crossed genetic heritage. The leaves are big and wavy, like turnips, but have a smooth surface with bluish bloom like cabbage. Some people find young rutabaga leaves quite palatable, but if you are looking for super nutrition from rutabagas, sprouts are the way to go. Rutabaga sprouts are loaded with antioxidants.

Rutabaga growth slows as the days become short, and the oldest leaves often shrivel and may be cut away. The roots will push up as they gain size, and garden-grown rutabagas tend to be more top-shaped than round.

“Fall — The best rutabagas are harvested from cool soil after autumn leaves start to fall.

It is always best to leave rutabagas in the ground until they get nicely chilled but not frozen. After the first frost passes, harvest your rutabagas during a period of dry weather. Pull the plants, trim off long roots and tops, and wash the roots lightly before letting them dry for a day in a cool place. Then store them in plastic bags in the refrigerator, or packed in damp sand or sawdust in a cold basement. They will keep in good condition for two months or more, should they last that long.

My Swedish grandmother made a rutabaga-potato mash called rutamouse, which resembles Scottish neeps and tatties, or perhaps clapshot in Orkney. By any name, a buttery mash of potatoes and rutabaga is a wonderful dish for a brisk fall day.