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When to Plant Kohlrabi in Grant County, KS

Grant County, Kansas Zone 6b May

May to-do list for Grant County, Kansas

Your Grant County, Kansas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 21
Avg. first frost October 17
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Get kohlrabi seeds going inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

To set up a strong June, finish these tasks
  • First harvests: 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.

Grant County, Kansas is in USDA Zone 6b. The average last spring frost is April 21 and the first fall frost is October 17, giving you a growing season of approximately 179 days.

At an elevation of 1,096 feet, Grant County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Kohlrabi during the growing season.

Grant County, KS (Zone 6b) Moderate season
179 days
Last Spring Frost April 21
179 growing days
First Fall Frost October 17

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (95 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 4 – Jul 9
Recommended (50%) ✓ Fits season (95 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 9 – Jul 14
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 22 – Jul 27

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 Grant County

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

Soil pH

Your soil pH (6.4–7.7) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — 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

4
successive plantings in your 179-day season

Sow every 5.1 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 208 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3" 3" 0" ✅ Rainfall sufficient
May 3" 2.8" 0.2" 💧 Light watering
Jun 3" 1.9" 1.1" 💧 Light watering
Jul 3" 2" 1" 💧 Light watering
Aug 3" 2.7" 0.3" 💧 Light watering
Sep 3" 2.4" 0.6" 💧 Light watering
Oct 3" 2.1" 0.9" 💧 Light watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Grant 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 ~756 GDD — county provides 2,461 GDD Excellent fit

Kohlrabi Planting Timeline — Grant County, KS

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 7 Apr 7 – Apr 28
Harvest June 9 Jun 9 – Jul 14
Fall Sowing August 8 Aug 8 – Aug 22

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

179 days in Grant County

Growing Tips for Kohlrabi in Grant County

Direct sow Kohlrabi outdoors after April 21 in Grant County when soil has warmed and frost danger has passed.

Your generous 179.0-day season in Grant 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 Grant County, KS?

Grant County is in Zone 6b with an average last frost of April 21. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, KS?

Grant County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 21 and first fall frost is October 17.

🌱

Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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