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When to Plant Kohlrabi in Linn County, KS

Linn County, Kansas Zone 6b May

This month in Linn County, Kansas

Each item below is timed to Linn County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Sow kohlrabi in trays indoors

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

  2. Harvest kohlrabi as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in June — start thinking about
  • 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.

Linn County, Kansas is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 434 feet, Linn County receives approximately 33 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Kohlrabi during the growing season.

Linn County, KS (Zone 6b) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25
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Linn County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 23 – Jun 27
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jul 2
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 10 – Jul 15

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 Linn County

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

Soil pH

Your soil pH (6.6–7.2) is within Kohlrabi's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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 199-day season

Sow every 5.1 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Only during dry spells
Season total 7 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 3" 3.5" 0" ✅ Rainfall sufficient
May 3" 5.4" 0" ✅ Rainfall sufficient
Jun 3" 4.6" 0" ✅ Rainfall sufficient
Jul 3" 4.2" 0" ✅ Rainfall sufficient
Aug 3" 4.5" 0" ✅ Rainfall sufficient
Sep 3" 2.6" 0.4" 💧 Light watering
Oct 3" 2.3" 0.7" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Linn 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 ~798 GDD — county provides 2,885 GDD Excellent fit

Kohlrabi Planting Timeline — Linn County, KS

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Harvest May 28 May 28 – Jul 2
Fall Sowing August 16 Aug 16 – Aug 30

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6b

📆 Growing Season

199 days in Linn County

Growing Tips for Kohlrabi in Linn County

Direct sow Kohlrabi outdoors after April 09 in Linn County when soil has warmed and frost danger has passed.

Your generous 199.0-day season in Linn 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 Linn County, KS?

Linn County is in Zone 6b with an average last frost of April 9. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Linn County, KS?

Linn County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 25.

🌱

Your Linn County Garden Planner — Free

A 24-page printable planner built for Linn 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 Linn 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.