Green gardening: growing turnips and rutabagas

Turnips are small-rooted vegetables, closely related to the large-rooted rutabagas (also known as swede turnips). Both turnips and rutabagas are cool-weather vegetables and are commonly grown as fall crops. Follow these guidelines to start your own crop.

Because they are planted in summer, turnips and rutabagas have the advantage of being suitable as succession crops in the space, for example, where you have finished harvesting spinach, peas, or early potatoes.

Depending on the variety, turnips need six to eight weeks to grow to maturity; rutabagas, about three months.

Popular turnip varieties: 

'Purple-Top White Globe', 'Tokyo Cross', and 'Just Right.'

Turnips grown primarily for greens:

'Foliage' and 'Seven Top.'

Popular rutabaga varieties:

'Laurentian', 'Altasweet' and 'Macomber.'

• To prepare the soil for turnips and rutabagas, dig it up and rake it thoroughly.
• If the soil has not been fertilized for a previous crop, spread a three-centimetre (one-inch) layer of compost over the planting area, and rake it in.

• Sow the seeds in shallow furrows, about one centimetre (half an inch) deep, in rows 30 to 60 centimetres (12 to 25 inches) apart.
• To prevent the soil from crusting, which makes it difficult for seedlings to break through, cover the seeds with a mixture of sand and soil.
• As soon as the seedlings germinate, thin them to stand about three centimetres (one inch) apart.
• A later, second thinning when the plants are eight to 10 centimetres (three to four inches) tall should leave turnips standing 10 centimetres (four inches) apart, rutabagas 12 centimetres (five inches) apart.

As with all root crops, turnips and rutabagas must be kept weed free so that their roots can develop. A light mulch will help smother weeds as well as retain moisture. Weeds should be pulled by hand or hoed out carefully to avoid disturbing the tops of the roots, which grow close to the surface and sometimes push through it.

Turnips are at their tenderest when they are five to eight centimetres (two to three inches) in diameter. If left to grow much larger, they become hard and lose their flavour. Although turnips grow sweeter with a slight touch of frost, they must be harvested before hard frost sets into the ground.

Store the turnips that you cannot use right away by burying them in moist sand and keeping them in a cool place.Turnip leaves can be harvested when they reach edible size. You can use the tops from thinnings or cut larger leaves from more mature plants. If you want a root harvest as well, cut only a few leaves from each plant.

Rutabagas are ready to eat when eight centimetres (three inches) across, but they can be left to grow until they are much larger. However, their flesh coarsens if they grow beyond 12 to 15 centimetres (five to six inches). They keep well when stored in moist sand in a cool place. They can also be left, well mulched, in the ground in freezing weather and dug up later.

• To avoid maggot problems, cover areas planted with turnips or rutabagas immediately after sowing seeds and keep plants covered until harvest.
• If plants are uncovered, try dusting hot pepper on the soil surface around them to repel the flies.
• If you see aphids feasting on the undersides of the leaves, blast them off with a hard stream of water.
• Insecticidal soap will kill the aphids.
• To combat striped flea beetles, which can eat hundreds of tiny holes in leaves, spray leaves with kaolin clay.
• Another option is to introduce some repellent plants, such as garlic.