Kohlrabi is a member of the cabbage (crucifer or mustard) family. The edible part is the enlarged stem or bulb above ground from which leaves develop. Kohlrabi may be white, green or purple. Leaves of young plants may be used like spinach or mustard greens. 

Kohlrabi will grow to be about 12 to 18 inches tall and the leaves will spread somewhere between two and 3 feet. Kohlrabi that is planted too close together will not get the light it needs for good bulb formation. Thin plants to stand at least 6 inches apart; 12 inches to produce the largest bulbs possible.
Kohlrabi is grown as a cool season vegetable and should be planted in very early spring or in summer for a fall harvest.  For a spring crop start seeds indoors or buy seedlings.
In late June or early July plant seeds about 1/4 inch deep in rows about 2 feet apart and thin to 4 inches apart in the row.  SHADE CLOTH COVERING HELPS SEEDLINGS DEAL BETTER WITH SUMMER HEAT. Ample soil moisture and high soil fertility are necessary for rapid growth of quality kohlrabi. Kohlrabi is ready to harvest 30 to 40 days from the date seed is sown. Kohlrabi is ready to harvest when it gets to the size of a tennis ball and is easily marked when pressed with a fingernail. The harvest for Kohlrabi usually lasts 2 to 3 weeks so it is a good idea to plant a few successions. 


Month to Month Care for Kohlrabi

Month of January 

This cool-season cole crop produces a turnip-flavored swollen stem in as little as 6 weeks. Six to eight plants are enough for learning whether you like it.  It comes green or purple but the inside is always white.

Month of February

 Prefers well-drained, fertile soil high in organic matter, pH 6.0 to 7.5. Can tolerate slightly alkaline soil. This heavy feeder also needs plentiful, consistent moisture.

Month of March

 If you want to use seeds instead of seedlings from the garden center, start seeds indoors six to eight weeks before the last frost date. 

Month of April

Seedlings should be at least four weeks old and have two to four leaves and a stem half as thick as a pencil.  Plant them about two to three weeks before the expected last frost date for your area. Mix slow-acting granular fertilizer into the soil when you prepare the planting area. Dig holes in the planting bed about 12 inches apart.

While they can handle cool weather, it is best to protect them from a surprise late frost.  Be prepared to cover the tender plants temporarily with white polyspun garden fleece, newspaper cloches, or a cold frame. They also do well in Walls O Water plant protectors. 

 Month of May

 Kohlrabi likes to have 2 to 3 inches of organic mulch to help keep moisture in the soil.

Optional - consider feeding the plants with liquid fertilizer about three weeks after planting.

Month of June

 This plant likes about 1 inch of water a week.

Kohlrabi will keep fresh in the refrigerator in a plastic bag for up to two weeks.

Optional - If temperatures reach the 80’s before you harvest all your Kohlrabi, spread shade cloth over the Kohlrabi plants to keep them a bit cooler and encourage more growth.

Optional Fall Crop - Plan to start harvesting at least a month before killing frost in your area, so start new seedlings right in the garden in late June or early July. Make sure to place the seeds ¼ to ½ inch deep into the soil about two to five inches apart if planting seeds directly outside. Actually kohlrabi tastes better in the fall after a frost than it does in the spring.

Month of July

 If eating raw, peel kohlrabi root to expose the white inner flesh, then cut as desired. It is great shredded into a salad. 

If eating cooked, wait to peel until after cooking. Bake in a covered dish with a few tablespoons of liquid at 350F / 180C, 50-60 minutes. Covered with light cheese sauce is wonderful. Boil covered, 30-35 minutes. Microwave whole trimmed kohlrabies in covered dish with a few tablespoons of liquid, 6-9 minutes. Sauté shredded peeled kohlrabi; first sprinkle with salt and let sit 30 minutes, then squeeze water out.

Optional - Using shade cloth over the seedlings in the first 6 to 8 weeks helps produce stronger plants in the fall.

Month of August

Don’t forget to mulch the new seedlings once they are 5 or 6 inches tall.

Month of September

 You want to make sure to keep the soil well watered or you will end up with woody stemmed plants that are too tough.

Month of October

 Long after hardy Swiss Chard succumbs to the cold and freezes of late autumn, the hardy Kohlrabi lives on. A little snow is of little worry for this hardy plant. If the weather is expected to go into the low twenties, you can cover any remaining plants for a day or two until the temperature inches up a bit.

Month of November

Mature kohlrabi withstand even severe frosts--indeed, the plant can be left in the ground right through winter--but young plants may bolt if they see, say, a week of temperatures at or below 50°F. (daily highs, that is).


 Kohlrabi in good soil has few insect or disease problems.  In lousy soil possible problems include: 

Holes In Leaves -  Cabbage Loopers
White Butterflies; Ragged Holes In Leaves, Bit Of Green Excrement On Leaves - Imported Cabbage Worm
Holes In Leaves - Caterpillar Of Diamondback Moth
Young Plant Severed At Soil – Cutworm
Tiny, Black Hopping Insect, Shot Holes In Foliage - Flea Beetles
Leaves Wrinkled Or Curled; Discolored, Stunted, Tend To Fall Off -  Aphids
White Powder On Leaf Undersides; Foliage Wilts - Downy Mildew, A Fungal Disease
Plants Chewed To Soil – Deer
Plant Chewed To Soil – Rabbits
Plant Chewed To Soil - Woodchucks
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