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When to Plant Radish in Fulton 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.

Fulton County, Illinois is in USDA Zone 5b. The average last spring frost is April 20 and the first fall frost is October 16, giving you a growing season of approximately 179 days.

At an elevation of 1,162 feet, Fulton County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Radish to ensure they mature before fall.

Fulton County, IL (Zone 5b) Moderate season
179 days
Last Spring Frost April 20
179 growing days
First Fall Frost October 16

Fulton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Transplant: Apr 14 🍅 Harvest: May 12 – Jun 2
Recommended (50%) ✓ Fits season (130 days to spare)
Transplant: Apr 20 🍅 Harvest: May 18 – Jun 8
Safe Start (90%) ✓ Fits season (131 days to spare)
Transplant: May 2 🍅 Harvest: May 30 – Jun 20

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 117 gal / 100 sq ft
Radish needs ~349 GDD — county provides 2,192 GDD Excellent fit

Radish Planting Timeline โ€” Fulton County, IL

Radish Planting Calendar

Activity When Date Range
Direct Sow April 6 Apr 6 โ€“ Apr 27
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest May 4 May 4 โ€“ May 25

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

22โ€“35 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

179 days

Growing Tips for Fulton 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Radish in Fulton County, IL?

Fulton County is in Zone 5b with an average last frost of April 20. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Fulton County, IL?

Fulton County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 20 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Fulton County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Fulton County, IL. Local conditions may vary. Last updated: April 2026.