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When to Plant Kohlrabi in Brown County, OH

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.

Brown County, Ohio is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 1,146 feet, Brown County receives approximately 32 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Kohlrabi during the growing season.

Brown County, OH (Zone 6a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Brown County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 29 – Jul 3
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 6 – Jul 11
Safe Start (90%) ✓ Fits season (100 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 26 – Jul 31

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.

Soil Compatibility in Brown County

How your county's soil matches Kohlrabi's growing requirements.

Soil pH

Your soil pH (6.0โ€“6.9) is within Kohlrabi's preferred range (6.0โ€“7.5).

Soil Texture

The silt loam soil in Brown County is excellent for Kohlrabi โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is excellent (4.8%) โ€” Kohlrabi will thrive.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

5
successive plantings in your 189-day season

Sow every 5.1 weeks. Last sowing by Aug 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 401 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Kohlrabi

Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Kohlrabi Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2" 0" โ„๏ธ Dormant
Apr 3" 2.9" 0.1" ๐Ÿ’ง Light watering
May 3" 4.1" 0" โœ… Rainfall sufficient
Jun 3" 4.1" 0" โœ… Rainfall sufficient
Jul 3" 3.5" 0" โœ… Rainfall sufficient
Aug 3" 3.2" 0" โœ… Rainfall sufficient
Sep 3" 2.7" 0.3" ๐Ÿ’ง Light watering
Oct 3" 2.3" 0.7" ๐Ÿ’ง Light watering
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Brown County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Kohlrabi Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Kohlrabi needs ~880 GDD — county provides 3,024 GDD Excellent fit

Kohlrabi Planting Timeline โ€” Brown County, OH

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors April 18 Apr 18 โ€“ May 2
Direct Sow April 4 Apr 4 โ€“ Apr 25
Harvest June 6 Jun 6 โ€“ Jul 11
Fall Sowing August 15 Aug 15 โ€“ Aug 29

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 Transplant Outdoors
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“65 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

189 days in Brown County

Growing Tips for Kohlrabi in Brown County

Direct sow Kohlrabi outdoors after April 18 in Brown County when soil has warmed and frost danger has passed.

Your generous 189.0-day season in Brown County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.

Common pests for Kohlrabi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kohlrabi in Brown County, OH?

Brown County is in Zone 6a with an average last frost of April 18. Plan your Kohlrabi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Brown County, OH?

Brown County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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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 Brown County, OH. Local conditions may vary. Last updated: April 2026.