Purple Vienna

Family: Brassicaceae Brassica

Sweetly crisp and vividly colored, Purple Vienna kohlrabi forms a smooth, globe-like bulb in a rich violet-purple that deepens as it matures.

The flesh is tender and fine-grained with a clean, mild bite—ideal for fresh snacking, quick roasting, and brightening into slaws and slaw-style salads. Grow it for a striking garden centerpiece and a reliable 55-day harvest that keeps well for weeknight variety and effortless serving.

Light: Full SunMaturity: 55 DaysHabit: Upright

Planting schedules and alerts are optimized for Columbus (Zone 6b).

Crop Dates

Milestone	Date
Start Indoors	Mar 28th
Last Frost	Apr 25th
Transplant / Sow Outdoors	Apr 25th
Harvest Begins	Jun 19th
Harvest Ends	Oct 16th

Crop Details

Trait	Value
Days to Maturity	55
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	45
Min Soil Temp (°F)	45
Min Night Temp (°F)	32
Harden Off (days)	6

Culinary Notes

Chef's Note

Purple Vienna’s fine-grained, sweet-crisp flesh makes it feel more delicate than typical cabbagey brassicas—fast cooking keeps the bite intact instead of turning tough. It’s built for brightness (lemon/vinegar) and dairy (butter or yogurt), where its mild bite stays lively rather than cabbage-sour.

Best Uses

shaved or matchsticked kohlrabi slaw under a bright, vinegar-forward dressing
quick sauté or roast until edges bronze while the center stays crisp-tender
hot sheet-pan toss with butter, lemon, and a little pepper for a fast side
thin-sliced snacking with salt, yogurt, or herby dips

Flavor Profile

sweet, snappy crunch clean mild brassica bite fine-grained tender flesh holds shape without going starchy quickly

Kitchen Pairings

lemon vinegar (cider or sherry) butter yogurt caraway gruyere

Frequently Asked Questions

What pest or disease most commonly affects Brassica oleracea var. gongylodes (purple Vienna kohlrabi), and how can I control it?

Watch for cabbage worms (imported cabbage worm/other lepidopteran larvae) that chew holes in kohlrabi leaves and can damage the developing stem. Check plants 2–3 times per week and hand-pick larvae early, then cover with fine insect netting once seedlings emerge to prevent egg-laying. If damage is widespread, use an approved Bt (Bacillus thuringiensis) spray targeted to caterpillars, following the label rate and reapplication interval.

How often should I water purple Vienna kohlrabi during the main growing phase to avoid problems?

During the active growth period (roughly weeks 3–6), keep the soil evenly moist but not waterlogged—aim for about 1 inch (2–3 cm) of water per week, split into 1–2 sessions as needed. Let the top 1 inch of soil dry slightly between waterings to prevent rot while avoiding long dry spells that can cause woody, tough bulbs. Mulch around plants to stabilize moisture and reduce moisture swings that lead to cracking or poor texture.

When is purple Vienna kohlrabi ready to harvest, and how do I know?

Harvest at about 55 days after sowing/transplanting, when the stem bulb is about 2–3 inches (5–8 cm) in diameter for best tenderness. The skin should look firm and smooth with a vibrant purple color, and the bulb should feel heavy for its size. If you wait too long, the bulb becomes pithy and woody—cut it promptly and harvest before it oversizes.