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When to plant Kohlrabi in McLean County, IL

The best window to plant Kohlrabi in McLean County, is April 4–April 25, when soil warms to 50°F. Last frost typically hits April 18; first frost October 18. A second sowing from August 9 to August 23 extends the harvest into fall.

When to Plant Kohlrabi in McLean County, IL

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.

McLean County, Illinois is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 18, giving you a growing season of approximately 183 days.

At an elevation of 1,024 feet, McLean County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Kohlrabi during the growing season.

McLean County, IL (Zone 6a) Moderate season
183 days
Last Spring Frost April 18
183 growing days
First Fall Frost October 18

McLean County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Monthly Watering Guide for Kohlrabi

Kohlrabi needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Kohlrabi Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in McLean County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kohlrabi Planting Timeline — McLean County, IL

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest June 6 Jun 6 – Jul 11
Fall Sowing August 9 Aug 9 – Aug 23

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

Moderate — regular watering

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in McLean County

Growing Tips for McLean County

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 McLean County, IL?

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

What planting zone is McLean County, IL?

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

When should I plant Kohlrabi in McLean County, IL?

In McLean County, IL, plant Kohlrabi after the last frost (around April 18) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is McLean County, IL for Kohlrabi?

McLean County sits in USDA Zone 6a. Kohlrabi grows reliably in zones 2a through 11b, so it's a good fit here.

Can Kohlrabi grow in McLean County's climate?

Yes — Kohlrabi grows well in McLean County's temperate climate. McLean County averages a 183-day frost-free season, with last frost around April 18 and first frost around October 18.

🌱

Your McLean County Garden Planner — Free

A 22-page printable planner built for McLean 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 McLean County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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