SproutSmart
SproutSmart Intelligent Garden Sowing

Kossak

Family: Brassicaceae Vegetable

Planting Schedule

Add Kossak to your garden to build a schedule and get reminders.

Tender, sweet-snap Kossak kohlrabi forms a smooth, globe-like bulb that rises boldly above the soil—its skin a clean, luminous pale green with a faint blush where light kisses it.

The flesh is crisp and juicy, with a fine, succulent texture that stays pleasantly mild even as it nears maturity. Grow Kossak for fresh salads, quick roasting, and bright slaws, or for creamy sauces that showcase its gentle, cabbage-sweet character.

Light: Full SunMaturity: 75 DaysHabit: Rosette

Botanical illustration of Kossak

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

Crop Dates

MilestoneDate
Start IndoorsMar 28th
Last FrostApr 25th
Transplant / Sow OutdoorsApr 25th
Harvest BeginsJul 9th
Harvest EndsOct 16th

Crop Details

TraitValue
Days to Maturity75
Sun RequirementsFull SunFull sun
Growth HabitRosette
Support NeededNone
Planting DepthNormal
Germination Temp (°F)45
Min Soil Temp (°F)40
Min Night Temp (°F)30
Harden Off (days)6

Culinary Notes


Chef's Note

Kossak kohlrabi is engineered for the kind of eating where you hear the crunch—its juicy, mild flesh sweetens without getting cabbagey, even when it’s close to mature. Slice it thin for salads or roast it hot for caramel edges, then season hard with citrus or butter so the brassica sweetness pops.

Best Uses

  • paper-thin slices in vinegar-slick salads where it stays snappy
  • quick roast or hot-sear to caramelize the edges while keeping the core tender
  • shaved or julienned slaw with a creamy or tangy dressing
  • blended into a silky sauce or purée with dairy or olive oil for a gentle vegetable sweetness

Flavor Profile

sweet, cabbage-mellow bite crisp, juicy snap mildly peppery brassica finish

Kitchen Pairings

lemon olive oil butter mustard fresh dill parmesan

Frequently Asked Questions


What pest or disease commonly affects kohlrabi (Brassica oleracea var. gongylodes), and how can I manage it at home?
Kohlrabi is commonly hit by cabbage worms (imported cabbageworm/diamondback moth larvae) and aphids; look for holes in leaves and sticky leaves or clusters of insects. Hand-pick larvae early and spray with Bacillus thuringiensis (Bt) labeled for caterpillars on Brassicas, and blast aphids off with a firm water spray before they multiply. If you see black-brown spots and leaf yellowing, remove affected leaves promptly and avoid wetting foliage to reduce spread of fungal leaf diseases.
How often should I water kohlrabi during the main growing phase?
During the 6–8 weeks when the bulb forms, keep soil consistently moist but not waterlogged—aim for about 1 inch (2.5 cm) of water per week, adjusting for heat and container use. Let the top 1 inch of soil dry slightly between waterings to prevent rot while maintaining steady growth; irregular watering can cause woody, pithy bulbs. Mulch helps hold moisture so the swelling globe forms smoothly.
How do I tell when kohlrabi is ready to harvest (75 days)?
Harvest when the globe (swollen stem) is firm and roughly 2–4 inches (5–10 cm) across, typically around 75 days from sowing depending on conditions. If it looks much larger and starts to feel hard or fibrous, it will likely be tough and more pungent. Use a knife to cut the bulb at the base, and harvest promptly rather than letting it sit.