When to Plant Radish in Champaign 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.
Champaign County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.
At an elevation of 1,215 feet, Champaign County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Radish during the growing season.
Champaign County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Champaign County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Radish's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Champaign County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Radish will thrive.
How to Plant Radish
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Sep 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 10.
Plant Water Budget
Radish Planting Timeline — Champaign County, IL
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Fall Sowing | August 10 | Aug 10 – Aug 24 |
| Harvest | April 28 | Apr 28 – May 19 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
22–35 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
188 days in Champaign County
Growing Tips for Radish in Champaign County
Direct sow Radish outdoors after April 14 in Champaign County when soil has warmed and frost danger has passed.
Your generous 188.0-day season in Champaign 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
Level Up Your Garden
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Champaign County, IL?
Champaign County is in Zone 5b 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 Champaign County, IL?
Champaign County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 19.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Champaign County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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