Days to germination: 2 to 5 days
Days to harvest: 30 to 60 days
Light requirements: Full sun or slight shading
Water requirements: Consistent but not excessive watering
Soil: Loose, even sandy soil
Container: Yes, in larger containers
Turnips are a good crop to grow for many reasons. They can give you a sizable crop in a very short time, and they are one of the easier plants for the home gardener.
Known best for their large roots, turnip greens can also be eaten. They can be strongly flavored and are usually cooked. Raw turnip roots are sometimes added for a crisp addition to summer salads but turnip is more often used as a cooked vegetable as well. They are good sources of vitamin C, and there is a lot of vitamin A in the greens. Turnips are high in fiber and low in calories.
Do not confuse turnip with rutabaga. They look quite similar but are not the same vegetable. Sometimes the turnip is referred to as the summer turnip, and the rutabaga as the winter turnip. Make sure you buy the right seeds so you know what you are planting.
Traditional turnips have round roots that are purple on top and white on the bottom, but several all-white varieties can be found. The leaves are always green though.
Starting from Seed
A cool-weather vegetable, turnips do best in spring and fall. You can easily plant for two crops, and its fine to direct seed into the garden in either season.
For your first planting, get the seeds out into the garden about 3 to 4 weeks before your expected last frost date. For the second crop, plant your seeds with enough time to let your plants reach maturity before the first hard frost. Seeds shouldn’t be planted deeply, just a half inch under the soil. Keep your soil moist and the seeds should sprout quite quickly.
Your soil should be very loose and well-dug so the turnip roots can grow without difficulty. When preparing the soil, add a dose of standard fertilizer mix as well.
Allow for 4 to 6 inches between your plants, though you can always seed them closer and thin out the younger plants as they grow. That’s a great option for getting some very young turnips and fresh greens in the spring.
As is usually the rule with root vegetables, you need to keep your watering as even as possible. Though you can’t control the weather, having very well-drained soil helps keep excessive water away from the roots. And if you are watering by hand in a dry spell, don’t let the plants dry out and then soak them. Uneven moisture will cause the roots to grow at an uneven rate, and they will split open.
Turnips would enjoy some fertilizer through the season, as long as you keep it to low nitrogen formulas. Nitrogen is great for leaves but will stunt roots.
If you’ve seeded out for a fall crop, you should try to shade your seedlings during the summer heat. They’ll want the full sun later on when the weather cools, so don’t plan your garden so they are in permanent shade. Fall turnips could be planted next to plants that are at full height in the summer (tomatoes, for example) that will temporarily shade them in the heat.
You don’t need to watch for your plants going to flower because turnips are biennial, meaning they take 2 years to finish their life cycle. If you were to leave turnip roots in the ground over the winter, they would likely continue to grow and produce seeds the second year. Turnips aren’t good to harvest the second year though, just the seeds.
You can definitely grow turnips in containers, providing they are at least a foot deep. One or two plants will do quite well, and you can plant more if you are going to pull them while they are still young and small.
Your pot will need good drainage, and take care not to water too much.
Pests and Diseases
Turnips are in the same plant family as broccoli and cabbage, so are prone to the same insect pests as these other vegetables. In particular, you need to watch out for cabbage root maggots. Small flies will lay their eggs around your plants in the spring, and the newly hatched worms will dig into your turnip roots and ruin them.
Your best defense is to keep the flies away in the first place. In the early spring, cover your turnip plants with a mesh net cover. When the warmer weather arrives, you should be more or less safe from the egg-laying flies and the covers can come off. It may take a season or two to get the timing right.
Tiny flea beetles and aphids can damage the leaves, particularly in large numbers. Pyrethrin sprays or Rotenone can repel them though you shouldn’t apply either to the leaves if you are about to harvest the greens.
Don’t plant turnips or any other Brassicas in the same spot each year to help keep the insect population under control.
Harvest and Storage
The longer you wait to pick your turnips, the larger they will get but you are also risking damage by root maggots at the same time. It’s best to start pulling your turnips when they reach a usable size rather than waiting to get them as large as possible. They will taste better anyway. After their maturity point, the roots will start to get woody. Depending on the variety, they will be 2 to 4 inches across.
Smaller turnips can be pulled up by their leaves but you will probably want to use a small shovel to dig out larger ones.
Turnips are well-known as vegetables great for root cellar storage through the winter. Granted, not everyone has a root cellar these days so you’ll have to find a very cool, dark and humid place to store your turnips if you want them to last for months. Rutabaga’s are better for longer-term storage than turnips.
You can also freeze cooked turnip for later use as well. For more immediate use, a whole turnip will keep fine in the fridge for up to 2 weeks (but don’t wash them first). Turnip greens don’t keep very long so use them within a few days of picking.