Purple Vienna Kohlrabi is a pre-1860 heirloom from northern Europe that brings vibrant purple bulbs and crisp white flesh to cool-season gardens across zones 3-10. This compact, non-GMO variety reaches full harvest in just 50-60 days, producing tennis-ball-sized bulbs that taste mild and tender when picked at 2-3 inches in diameter. Its attractive purple skin, cabbage-like flavor, and ability to thrive in containers, raised beds, or garden plots make it a reliable cool-season choice for spring and fall crops. The young leaves are edible too, adding another layer of harvest from a single plant.
Photo © True Leaf Market
Growing Conditions
USDA Zone
3-10
Sunlight
Full Sun
Water
Moderate
Soil
Well-drained, Fertile Loam With Consistent Moisture
Preferred Temp60-75°F
Growth Stats
18 in
Height
18 in
Width
6 in
Spacing
50–60
Days to Harvest
PeriodAnnual
TypeBush
Plant Profile
Sunlight
Full Sun
Water
Moderate
Zones
3-10
Size
18in H x 18in W
Growth
Annual
Care
Moderate
Hover over chart points for details
Highlights
These purple bulbs are at their sweetest and most tender when harvested small, around 2-3 inches across, which means you'll be eating them at peak flavor within 8-10 weeks of planting. The white interior flesh stays crisp and juicy at that size but quickly becomes woody if left to grow beyond 4 inches, so timing your harvest is key to the full Purple Vienna experience. Both bulbs and young greens are edible raw or cooked, making this heirloom feel like two crops in one.
Common Uses
The tender bulbs are equally at home raw in slaws or salads as they are steamed, roasted, or sautéed. The young leaves work like kale or collards, excellent steamed on their own or added to soups and stir-fries. Many gardeners blanch and freeze the bulbs for winter use, or pickle them for a tangy condiment. The mild, turnip-like flavor makes it approachable for those new to kohlrabi, less assertive than some brassicas but still distinctly flavorful.
Growing Timeline
First Bloom
Does Not Bloom (Grown For Its Bulbous Stem)
First Harvest
50-60 Days After Planting
Last Harvest
Mid To Late Fall
Care Instructions
Start Indoors
Start seeds indoors 6 weeks before your last spring frost date, sowing at a depth of 1/4 to 1/2 inch. Transplant seedlings outdoors 3-4 weeks after sowing, timing them so they go into the garden 3-4 weeks before your last frost date. For fall crops, start seeds indoors 10-12 weeks before your first frost date and transplant in summer to mature during cool fall weather.
Transplant Outdoors
Transplant seedlings outdoors 3-4 weeks after sowing indoors, ideally 3-4 weeks before your last spring frost date. Space plants 6 inches apart in rows 12 inches apart. Harden off seedlings gradually before moving them outside. Soil temperature should be at least 45°F at transplanting, though 65-80°F is ideal for vigorous growth.
Direct Sow
Direct sow seeds in the garden 3-4 weeks before your last spring frost date, or when soil temperature reaches 45°F or warmer. You can also sow in late summer for a fall harvest. Sow seeds at a depth of 1/4 to 1/2 inch and thin seedlings to one plant every 4 inches once they reach 2 inches tall.
Harvesting
Harvest Purple Vienna kohlrabi when the bulbs are 2-3 inches in diameter for the best flavor and texture; this typically occurs 50-60 days after planting. At this size, the flesh is crisp, juicy, and tender. Do not let bulbs grow larger than 4 inches in diameter, as they will become woody and lose their pleasant texture. Young leaves can be harvested fresh from the plant and eaten raw or cooked at any point during the season. Cut the entire bulb at soil level with a clean knife, and harvest young foliage by pinching or cutting individual leaves.
Growing Calendar
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Companion Planting
Ecology & Traits
Edible
Scientific Classification
Brassica oleracea L. var. gongylodes L.
Family
Brassicaceae
Genus
Brassica
Duration
Annual
Growth Habit
Upright
Native Status
L48 (I)PR (I)CAN (W)GL (W)
History & Origin
“Purple Vienna Kohlrabi arrived in North America from northern Europe but remained a curiosity for decades. It didn't become common in United States gardens until after the Civil War, when seed companies began promoting this unusual-looking brassica more widely. As a pre-1860 heirloom, it represents the kind of vegetable that was preserved and passed through generations by gardeners who recognized its value, even when it seemed exotic to American growers. Today it persists as an open-pollinated, non-GMO variety, a living link to 19th-century European kitchen gardens.”