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When to plant Radish in Shelby County, IL

Plant Radish in Shelby County from March 31 to April 21 in spring. Shelby County sits in USDA Zone 6b, with last frost around April 14 and first frost on October 17. A second sowing from August 8 to August 22 extends the harvest into fall.

When to Plant Radish in Shelby County, IL

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Shelby County, Illinois is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 807 feet, Shelby County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Radish during the growing season.

Shelby County, IL (Zone 6b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Monthly Watering Guide for Radish

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

Month Radish Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 4.4" 0" ✅ Rainfall sufficient
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Radish Planting Timeline — Shelby County, IL

Radish Planting Calendar

Activity When Date Range
Direct Sow March 31 Mar 31 – Apr 21
Harvest April 28 Apr 28 – May 19
Fall Sowing August 8 Aug 8 – Aug 22

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

186 days in Shelby County

Growing Tips for Shelby County

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Shelby County, IL?

Shelby County is in Zone 6b with an average last frost of April 14. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, IL?

Shelby County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 17.

When should I plant Radish in Shelby County, IL?

In Shelby County, IL, plant Radish after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Shelby County, IL for Radish?

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

Can Radish grow in Shelby County's climate?

Yes — Radish grows well in Shelby County's temperate climate. Shelby County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.

🌱

Your Shelby County Garden Planner — Free

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

Sources & credits

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