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When to Plant Radish in Hardin 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.

Hardin County, Illinois is in USDA Zone 6b. The average last spring frost is April 4 and the first fall frost is October 31, giving you a growing season of approximately 210 days.

At an elevation of 1,218 feet, Hardin County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Radish during the growing season.

Hardin County, IL (Zone 6b) Long season
210 days
Last Spring Frost April 4
210 growing days
First Fall Frost October 31

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (159 days to spare)
Transplant: Mar 28 🍅 Harvest: Apr 25 – May 16
Recommended (50%) ✓ Fits season (161 days to spare)
Transplant: Apr 4 🍅 Harvest: May 2 – May 23
Safe Start (90%) ✓ Fits season (169 days to spare)
Transplant: Apr 17 🍅 Harvest: May 15 – Jun 5

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 Hardin County

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

Soil pH

Your soil pH (6.2โ€“7.2) overlaps with Radish's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Hardin County is excellent for Radish โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) โ€” Radish will thrive.

How to Plant Radish

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Radish

12
successive plantings in your 210-day season

Sow every 2.4 weeks. Last sowing by Sep 26 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Radish needs ~456 GDD — county provides 3,360 GDD Excellent fit

Radish Planting Timeline โ€” Hardin County, IL

Radish Planting Calendar

Activity When Date Range
Direct Sow March 21 Mar 21 โ€“ Apr 11
Fall Sowing August 22 Aug 22 โ€“ Sep 5
Harvest April 18 Apr 18 โ€“ May 9

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

210 days in Hardin County

Growing Tips for Radish in Hardin County

Direct sow Radish outdoors after April 04 in Hardin County when soil has warmed and frost danger has passed.

Your generous 210.0-day season in Hardin County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

Common pests for Radish 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 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 Hardin County, IL?

Hardin County is in Zone 6b with an average last frost of April 4. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hardin County, IL?

Hardin County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 4 and first fall frost is October 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hardin County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hardin County, IL. Local conditions may vary. Last updated: April 2026.