Kohlrabi is a hardy member of the cabbage family. The name is a German word meaning cabbage, describing the turnip-like enlargement of the stem above the soil. Kohlrabi is not a root vegetable.
The leaves stand out like spokes from the part you eat, the rounded stem section, which is commonly referred to a bulb. Although it is quite exotic looking, it is really just a different horticultural form of the species to which cabbage, kale, broccoli and cauliflower belong. It has a nice mild sweet cabbage flavor.
There are a number of both white and really light green and also purple cultivars.
Early White Vienna is a standard white variety with few leaves, 55 days maturity.
Early White Purple is a standard purple variety with flatter purplish leaves, 60 days maturity
Grand Duck produces vigorous small plants that are tolerant of black rot, matures in 45 days.
Granlibakken offers excellent texture and has a sweet and mild flavor, 45 days maturity.
Superschmelz is a giant type that grows uniformly large and remains very sweet and tender to the biggest sizes. You will get the best results with this cultivar when is sown in the summer for fall harvest, 60 days maturity. These seeds are available at www.territorialseed.com or www.rareseeds.com (Baker Creek Heirloom seeds)
Kohlrabi is easy to grow in full sun with a moist, well-drained soil rich in organic matter. Like other Cole crops, they do best in cool weather, but tolerate heat better than most members of the cabbage family. Sow seeds directly into the ground as soon as the soil is workable. For an earlier harvest, seeds can be started indoors 4-6 weeks before transplanting outdoors when the ground is ready. For a continuous supply through late spring and early summer, make small plantings every 2-3 weeks. Fall plantings should be sown in mid-summer. Plants are cold-tolerant and will survive in the garden long after the frost. Plan the planting so harvest will be a week or two after the first fall frost is expected.
Place the seeds 1/4-1/2 inch deep and thin seedlings to 2-5 inches apart, more if you are growing a larger variety. Keep the plants well watered as too much moisture will prevent the stems from becoming tough and woody. Cultivate carefully to avoid damaging the shallow roots. Fertilize before planting and again at mid-season.
Kohlrabi generally has few insect and disease problems. Plant disease resistant varieties when available and maintain vigorous plants. Avoid handling the plants when they are wet and remove any infected plants or plant parts.
Kohlrabi has the mildest and best flavor when small. Older kohlrabi tends to be tough and woody and it may have an off-flavor, except in some newer varieties, such as Gigante and Kossak that do not develop woody fibers in the enlarged stem. You can begin harvest when the bulbs are about one inch in diameter and continue harvesting until the bulbs reach the mature size for that variety. Pull the entire plant out of the ground, or cut it off at the ground level. The plant is excellent to eat raw or in stir fries and the leaves when small, then fried or steamed make a nice side dish with some butter and fresh herbs or salt and pepper.
Kohlrabi is an easy and carefree vegetable to grow, even if you just eat it raw you are adding vital nutrients to your body by eating the fresh vegetable in season.
Give it a try this year and you will become hooked to make it a regular in your garden every year. For some kohlrabi recipes go to my recipe blog cjinspirations.wordpress.com