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When to Plant Kohlrabi in Martin County, KY

Martin County, Kentucky Zone 6b April

Top priorities for Martin County, Kentucky gardeners in April

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Martin County, Kentucky.

Avg. last frost April 16
Avg. first frost October 27
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 13 hrs
  1. Transplant kohlrabi outside

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Plant kohlrabi from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Get ahead of May
  • Starting indoors: kohlrabi

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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.

Martin County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 1,188 feet, Martin County receives approximately 51.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Kohlrabi during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.

Martin County, KY (Zone 6b) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Martin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 29 – Jul 3
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 4 – Jul 9
Safe Start (90%) ✓ Fits season (107 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 21 – Jul 26

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 Martin County

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

Soil pH

Your soil pH (5.7–6.9) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Martin County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Kohlrabi.

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 194-day season

Sow every 5.1 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 4.7" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 5.4" 0" ❄️ Dormant
Apr 3" 4.3" 0" ✅ Rainfall sufficient
May 3" 4.2" 0" ✅ Rainfall sufficient
Jun 3" 4.3" 0" ✅ Rainfall sufficient
Jul 3" 4.5" 0" ✅ Rainfall sufficient
Aug 3" 4.1" 0" ✅ Rainfall sufficient
Sep 3" 4" 0" ✅ Rainfall sufficient
Oct 3" 3.6" 0" ✅ Rainfall sufficient
Nov 4.2" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Martin County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~839 GDD — county provides 2,958 GDD Excellent fit

Kohlrabi Planting Timeline — Martin County, KY

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 4 Jun 4 – Jul 9
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Martin County

Growing Tips for Kohlrabi in Martin County

Direct sow Kohlrabi outdoors after April 16 in Martin County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in Martin 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 Martin County, KY?

Martin County is in Zone 6b with an average last frost of April 16. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Martin County, KY?

Martin County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 27.

🌱

Your Martin County Garden Planner — Free

A 24-page printable planner built for Martin County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Martin County, KY. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.