When to plant Radish in Alexander County, IL
Alexander County's climate puts the Radish spring window between March 27 and April 17. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from August 12 to August 26 extends the harvest into fall.
When to Plant Radish in Alexander County, IL
Top priorities for Alexander County, Illinois gardeners in July
Here's what deserves your attention in Alexander County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
Before August arrives, get these ready
- Fall sowing: radish
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.
Alexander County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.
At an elevation of 1,260 feet, Alexander County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Radish during the growing season.
Alexander County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
Drainage
Well Drained
Radish 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 Alexander County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Radish's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Alexander County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Radish.
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 16 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
Radish Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Radish
Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Radish Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Alexander County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Radish Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Radish Planting Timeline — Alexander County, IL
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Harvest | April 24 | Apr 24 – May 15 |
| Fall Sowing | August 12 | Aug 12 – Aug 26 |
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 7a
📆 Growing Season
194 days in Alexander County
Growing Tips for Radish in Alexander County
Direct sow Radish outdoors after April 10 in Alexander County when soil has warmed and frost danger has passed.
Your generous 194.0-day season in Alexander 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
Check more plant combinations with our Companion Planting Checker →
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Alexander County, IL?
Alexander County is in Zone 7a with an average last frost of April 10. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Alexander County, IL?
Alexander County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 21.
When should I plant Radish in Alexander County, IL?
In Alexander County, IL, plant Radish after the last frost (around April 10) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Alexander County, IL for Radish?
Alexander County sits in USDA Zone 7a. Radish grows reliably in zones 2a through 11b, so it's a good fit here.
Can Radish grow in Alexander County's climate?
Yes — Radish grows well in Alexander County's temperate climate. Alexander County averages a 194-day frost-free season, with last frost around April 10 and first frost around October 21.
Your Alexander County Garden Planner — Free
A 22-page printable planner built for Alexander County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.