Time to Grow Turnips

19 August 2011, written by Barbara Pleasant

Fast-maturing and easy to grow, turnips always emerge as stars in the autumn garden. Sown after summer crops of onions, squash, beans or sweet corn, turnip seeds germinate within days, and tender greens are ready to pick within a month. Juicy roots come later, and you can grow turnips for greens, roots, or both. By growing different types of turnips, you can reap maximum reward from this ancient vegetable.

Turnip Types

I grow three different types of turnip, which are handled differently in the garden:

Oriental hybrids like 'Hakurei' and 'Market Express' produce sweet, white ping-pong ball size roots in only four to five weeks. Worthy of salads or stir fries, the mild-flavored roots are the best type of turnip to eat raw. And, because the roots are harvested while quite young, you can harvest the greens in one fell swoop, too. Steamed, chopped and frozen, young turnip greens can stand in for spinach in most recipes. Red turnips like 'Scarlet Queen' and 'Scarlet Ohno Revival' should be harvested young, too, as the roots tend toward slight bitterness as they age.
Yellow turnips like 'Yellow Globe' go under many different names, and many gardeners (including me) prefer the flavor of golden turnip roots for braising, roasting and grilling. Because I want big, smooth roots, I rarely harvest greens from my yellow turnips so the roots can grow steadily. Yellow turnips are at their best after a couple of light frosts have passed.
Purple top turnips like 'Purple Top White Globe' are the best choice for prolonged production of greens, and for leaving in the ground through winter for pollinator-friendly yellow flowers in spring. In my experience, purple top turnips respond to cutting by developing numerous leaf buds all over the top of the root, Medusa-style, which enhances their ability to produce even more savory, nutritious greens. If you want to grow turnips as a forage crop for homestead animals, purple top turnip is the type you want.

How to Plant Turnips

When planted after onions, potatoes, and other vegetable of summer, turnips are sometimes called a "mop up" crop because of their ability to utilize soil-borne nitrogen left from the previous crop. Still, I like to mix in standard application of a balanced organic fertilizer, watered in well, before planting turnip seeds. Additionally, deeply soaking the prepared bed helps encourage strong germination.

I like to grow yellow turnips in rows where I can carefully control weeds and spacing and thus get a uniform crop. Other turnips can be sown by broadcasting the seeds over a prepared bed, which works great as long as you can easily reach the center of the bed for thinning and harvesting. Broadcast-sown seeds can be firmed into soil crevices by tamping the soil's surface with the back of a rake.

In beds or rows, the only trick to getting turnip seeds to germinate is to keep them moist for about three days. In sunny weather, I cover the seeded bed with a piece of burlap to keep it moist throughout the day.

How to Grow Turnips

Turnip seed germination is fast and sure, and thinning is usually necessary. Yet turnips grow so quickly that a single session of thinning and weeding is all that is needed to help them dominate their space. Flea beetles and other small insects may make small holes in young turnip greens, but the plants are so vigorous that they quickly outgrow the damage. Indeed, the only special care turnips need is regular water. Keeping the soil lightly moist encourages the growth of luxuriant greens and big roots with no splits and cracks.

Turnip greens taste best when they are young and have been exposed to several days and nights of cool weather. Similarly, turnip roots accumulate sugars as soil temperatures decline. For these reasons, it's best to harvest the season's best turnips after light frosts have arrived, but before your first hard freeze.

Overwintering Turnips

Mature turnips are surprisingly cold hardy. I have had roots survive at 0°F (-18°C) under snow, even when nibbled by deer. Turnips that survive winter promptly produce sprays of yellow flowers in spring. Both the unopened flower buds and the green seed pods are edible, and make interesting additions to soups and salads. But mostly I allow a few plants to bloom to please honeybees, which gather the turnip nectar when it's barely warm enough to fly.

By Barbara Pleasant