Botanical Names: Brassica rapa
The turnip (Brassica rapa) is grown world-wide for its tasty, swollen lower stem and nutritious leaves. It is easy to grow during cool weather in many soils and matures very quickly from seed to table.
Some gardeners grow varieties developed specifically for their tender, slightly hairy leaves, called turnip greens, which loaded with vitamins A, B, C, and K, folate, iron, calcium, and thiamine. The young ones can be eaten raw, while older leaves are cooked like spinach or kale.
The bulbous turnip roots, which are roundish or conical and grow partly in the soil, are somewhat pungent and bitter when mature, but are low-calorie and very high in fiber, Vitamins A and C, and the same cancer-fighting compounds found in broccoli and cabbage. They can be eaten raw, roasted, boiled, or mashed, and are often combined with other root crops in stews.
Turnips are also highly valued as livestock feed, and can be left in fields to be grazed even under snow in the winter. Because of this, they are also planted by hunters, because the best flavors preferred by deer develop after cool weather – just in time for hunting season.
Most turnip roots are typically white both inside and out, though some can have red or yellow skin and yellow, red, or streaked flesh when mature. However, the most popular varieties have white roots which turn purple around the tops where the sun shines on them. There are many good selections, but the standard variety, named Purple Top White Globe, has smooth roots that are nearly round, and creamy white with bright purple shoulders. It can easily get the size of aman’s fist, but is much milder and sweeter when picked at only two or three inches in diameters.
Other great purple top turnips are Royal Crown and Royal Globe, which are modern hybrids, as opposed to the open-pollinated heirloom Purple Top White Globe.
How to Grow Purple Top Turnips
Purple turnips grow best in cool weather, and get hard and bitter when exposed to hot temperatures. So most gardeners plant them in late spring when soils reach 50F or more; because they will tolerate frost and light freezes, in areas with long growing seasons turnips can be planted again in late summer and fall.
They grow best in full sun and well-drained, moderately-fertile soils. Sow seed thinly across the soil, rake and tamp gently to cover seeds no more than about a quarter of an inch, and water lightly to get seeds starting to germinate. In warm soils seeds should come up within two weeks.
As the plants grow they need extra room, so thin them until the remaining plants are three or four inches or more apart. Small thinned plants can be cooked and eaten.
Harvest turnips greens as they grow, starting when they are small and leaving a few to develop larger roots. They will keep for weeks in the refrigerator, but for longer storage, store in a cool, dark, damp place.