Kohlrabi, German turnip, and turnip cabbage all the same name for this interesting member of the brassica family. It is a biennial grown as a annual in many gardens. Kohlrabi can be sown in spring or fall depending on your region. Modern Kohlrabi is relatively new about 500 years or so and was selectively grown in Northern Europe in the 1500s. Kohlrabi is a hardy cold weather crop with a taproot. It grows well in 5 gallon containers or garden. Despite its appearance the whole Kohlrabi is edible from leaves to bulb. It can be eaten cooked, or raw. The bulb grows just above the soils and can grow large. Easy to care for and grow.
Plant and go
Botanical: Brassica Oleracea gongylodes
| Depth: ¼-½" | Spacing: 6-8" | Row: 18-24" | Temp: 55-70F |
| Germ: 3-10 days | Sun: Full/Partial 6-8 hrs | pH: 6.5-6.8 | Harvest: 50-55 days |
| Soil: well drained | Container: 16x16" | Fertilizer: 10-10-10 | Fert Freq: 3-4 wks |
Details
The kohlrabi plant come in a few colors and varieties green and purple are the main colors. Pick a variety that works best for your area and space, they don’t like crowding it hinders bulb growth. Seeds can be started in spring or late summer. Spring planting direct sow when soil temperatures are about 45F or higher. Or, start indoors 6-8 weeks before last frost. For a fall harvest sow in mid to later summer. Plant seeds in loose soil with organic compost or fertilizer 1/4-1/2 inches deep, space 1-2 inches apart, rows at 10-12 inches apart. A grow tray may be useful it makes it easier to remove seedlings. Kohlrabi likes cooler temperatures from germination to maturity, 55-70F. Kohlrabi can tolerate lower temperatures around 24-28F for short period of time. Like many Cole crops Kohlrabi is heat sensitive, use shade as needed for your area. Germination can take 3-10 days, which can be sped up by pre-soaking seeds. Thin seedlings once they have a fee true leaves. Spacing goal is 9-12 inches, go slow and pick the ones you like. Depending on variety this plant likes 6+ hours of direct or partial sun. When it’s time to transplant start by hardening off the plants before moving outside permanently. Make sure to stager plants to optimize bulb growth. Transplant seedlings when they are 4-6 inches tall. Mulch with about a 1 inch of compost or preferred medium. Water weekly about 1 to 1.5 inches per week, avoid over watering. Once established wait until harvest time, keep a eye on pest and bulb development.
Harvest
Kohlrabi can take 50-55 days to mature. It’s very easy to tell if the plant is ready it will be about the size of a tennis ball. To harvest cut the stalk at ground level. Note, the stem is kinda tough, use garden shears to remove the bulb. Clean and store properly.
Tip
Kohlrabi are biennial. So, If the bulb is removed and the root system is left in tack the plant will grow back but only to complete its life cycle to seed.
Fun fact
The largest kohlrabi grown was in August 30, 2006 by Scott Robb of Palmer, Alaska. 96 pounds 15 oz.
Conclusion
Kohlrabi is a great challenge for those looking to try something new. The plant is a biennial and only grows one bulb. If you leave the plant intact after harvest it will flower. Don't crows your plant, water on a schedule and wait to harvest. And maybe wait to harvest after a frost or two. Cole plants are said to taste better after frosts.