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When to Plant Kohlrabi in Linn County, MO

Linn County, Missouri Zone 6a May

Your May gardening checklist

May is a pivotal month for Linn County, Missouri gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 17
Avg. first frost October 20
Soil temp (4") 57°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Get kohlrabi seeds going inside

    These need a head start before your last frost (April 17). Sow into cells now so you're ready to transplant in a few weeks.

Before June arrives, get these ready
  • 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, Missouri is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 20, giving you a growing season of approximately 186 days.

At an elevation of 880 feet, Linn County receives approximately 32.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Kohlrabi during the growing season.

Linn County, MO (Zone 6a) Moderate season
186 days
Last Spring Frost April 17
186 growing days
First Fall Frost October 20
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Linn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (101 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 30 – Jul 4
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 5 – Jul 10
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 18 – Jul 23

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 (5.5–6.8) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). 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

4
successive plantings in your 186-day season

Sow every 5.1 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3" 2.8" 0.2" 💧 Light watering
May 3" 3.5" 0" ✅ Rainfall sufficient
Jun 3" 3.7" 0" ✅ Rainfall sufficient
Jul 3" 3.5" 0" ✅ Rainfall sufficient
Aug 3" 3.8" 0" ✅ Rainfall sufficient
Sep 3" 2.9" 0.1" 💧 Light watering
Oct 3" 2.4" 0.6" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.8" 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 ~756 GDD — county provides 2,557 GDD Excellent fit

Kohlrabi Planting Timeline — Linn County, MO

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 3 Apr 3 – Apr 24
Harvest June 5 Jun 5 – Jul 10
Fall Sowing August 11 Aug 11 – Aug 25

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
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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 6a

📆 Growing Season

186 days in Linn County

Growing Tips for Kohlrabi in Linn County

Direct sow Kohlrabi outdoors after April 17 in Linn County when soil has warmed and frost danger has passed.

Your generous 186.0-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, MO?

Linn County is in Zone 6a with an average last frost of April 17. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Linn County, MO?

Linn County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 20.

🌱

Your Linn County Garden Planner — Free

A 24-page printable planner built for Linn County (Zone 6a). 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, MO. 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.