Unknown / CC0
Kohlrabi
Brassica oleracea var. gongylodes
Overview
An unusual brassica that forms a swollen, above-ground stem that looks like a vegetable from another planet — earning it the nickname 'Sputnik vegetable.' Despite its alien appearance, kohlrabi is mild, sweet, and crunchy when eaten raw, with a flavor between broccoli stem and apple. Purple and green varieties are equally delicious, and it matures quickly — often ready in just 45-60 days.
Kohlrabi (Brassica oleracea var. gongylodes) is a member of the Brassica genus, which includes various edible plants known for their distinctive cruciform flowers and unique flavor profiles. As part of this diverse family, kohlrabi shares several characteristics with its relatives.
Like other Brassica species, kohlrabi is an annual or biennial plant that thrives in cool temperatures. It typically grows between 12 to 24 inches tall, depending on the specific cultivar and growing conditions. The plant's leaves are dark green and form a rosette around the swollen stem, which is the edible part of the kohlrabi known as the bulb.
Growing Conditions and Care
Members of Brassica are generally hardy in USDA zones 4-9, making them adaptable to various climates. Kohlrabis, like their cousins, prefer well-draining soil with a slightly acidic to neutral pH (6.0-7.5). They require full sun exposure and can tolerate a range of moisture levels, although consistent watering is essential for optimal growth.
Ecological Significance
The Brassica genus is known for its diverse flowering habits, ranging from spring through fall, depending on the specific species. Kohlrabi typically matures within 50 to 70 days after planting, producing small, white or yellow cruciform flowers that attract pollinators and eventually form seed pods.
In summary, kohlrabi is a versatile and nutritious vegetable that belongs to the Brassica genus, which includes other popular crops such as cabbage, broccoli, and cauliflower. By understanding the typical characteristics of this diverse group of plants, gardeners can provide optimal growing conditions for their kohlrabis and enjoy the benefits of these flavorful and healthy vegetables.
Growing Conditions
Habitat & Range
- Habitat
- Meadows & Open Areas
- Native Range
- also native to France, Great Britain, Spain; introduced in 15 US states
- Cultivation Region
- Northern temperate regions
Botanical data via projectGAIA.
Companion Planting & Soil
Good Companions
Avoid Planting Near
Sowing & Propagation
Planting Calendar
When to sow, transplant, and harvest by growing zone.
| Zone | Action | Months | Notes |
|---|---|---|---|
| Cold (1-2) | Start Indoors | Mar — Apr | Start indoors 6 weeks before last frost |
| Cold (1-2) | Transplant | May — Jun | Transplant after last frost; handles light frost |
| Cold (1-2) | Harvest | Jun — Aug | Harvest at 2-3" diameter; gets woody if left too long |
| Cool (3-4) | Direct Sow | Mar — May | Direct sow in early spring; succession sow every 2-3 weeks |
| Cool (3-4) | Direct Sow | Jul — Aug | Fall crop; frost improves flavor |
| Cool (3-4) | Harvest | May — Jun | Harvest spring crop at 2-3" diameter |
| Cool (3-4) | Harvest | Sep — Oct | Harvest fall crop |
| Moderate (5-7) | Direct Sow | Feb — Apr | Sow in early spring |
| Moderate (5-7) | Direct Sow | Aug — Sep | Fall crop; matures in 55-65 days |
| Moderate (5-7) | Harvest | Apr — May | Spring harvest |
| Moderate (5-7) | Harvest | Oct — Nov | Fall harvest |
| Warm (8-9) | Direct Sow | Sep — Oct | Fall sowing; cool-season crop |
| Warm (8-9) | Harvest | Nov — Dec | Fall/early winter harvest |
| Hot (10+) | Direct Sow | Oct — Dec | Cool-season crop only |
| Hot (10+) | Harvest | Dec — Feb (wraps) | Cool-season harvest |
Uses
Culinary
- Sliced raw with dip or in salads for crisp sweetness
- Roasted or sautéed as a side dish
- Spiralized as a low-carb noodle alternative
Medicinal
- Rich in glucosinolates with cancer-protective properties
- High in vitamin C and potassium
- Good source of fiber and B vitamins
Other Uses
- Quick-maturing space-efficient vegetable
