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When to Plant Kohlrabi in Madison County, KY

Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.

Madison County, Kentucky is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 3,082 feet, Madison County receives approximately 53.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Kohlrabi during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.

Madison County, KY (Zone 6b) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Madison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: May 27 – Jul 1
Recommended (50%) ✓ Fits season (108 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 3 – Jul 8
Safe Start (90%) ✓ Fits season (100 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 20 – Jul 25

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Kohlrabi needs ~839 GDD — county provides 2,928 GDD Excellent fit

Kohlrabi Planting Timeline โ€” Madison County, KY

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 15 Apr 15 โ€“ Apr 29
Direct Sow April 1 Apr 1 โ€“ Apr 22
Fall Sowing August 15 Aug 15 โ€“ Aug 29
Harvest June 3 Jun 3 โ€“ Jul 8

Plant 0.5" deep ยท 4" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“65 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

192 days

Growing Tips for Madison County

Direct sow in spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

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Frequently Asked Questions

When should I plant Kohlrabi in Madison County, KY?

Madison County is in Zone 6b with an average last frost of April 15. Plan your Kohlrabi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Madison County, KY?

Madison County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Madison County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Madison County, KY. Local conditions may vary. Last updated: April 2026.