When to plant Radish in Jasper County, IA
For Jasper County, gardeners: plant Radish April 18 through May 9 once soil reads 50°F. A second sowing from July 29 to August 12 extends the harvest into fall.
When to Plant Radish in Jasper County, IA
June in Jasper County, Iowa — your action list
Welcome to June in Zone 5b. These are the moves that will have the biggest impact on your growing season.
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Harvest radish as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong July, finish these tasks
- 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.
Jasper County, Iowa is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.
At an elevation of 1,048 feet, Jasper County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Radish during the growing season.
Jasper County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.7
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 Jasper County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (6.0–6.7) is within Radish's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Jasper 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 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 29.
Radish Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 4" | 0" | ❄️ Dormant |
| May | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Jasper 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 — Jasper County, IA
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 18 | Apr 18 – May 9 |
| Harvest | May 16 | May 16 – Jun 6 |
| Fall Sowing | July 29 | Jul 29 – Aug 12 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow Harvest |
| June | Harvest |
| July | Fall Sowing |
| 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: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
158 days in Jasper County
Growing Tips for Radish in Jasper County
Direct sow Radish outdoors after May 02 in Jasper County when soil has warmed and frost danger has passed.
Your generous 158.0-day season in Jasper 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 Jasper County, IA?
Jasper County is in Zone 5b with an average last frost of May 2. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jasper County, IA?
Jasper County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 7.
When should I plant Radish in Jasper County, IA?
In Jasper County, IA, plant Radish after the last frost (around May 2) and before the first frost (around October 7). Best results when soil holds above 50°F.
What growing zone is Jasper County, IA for Radish?
Jasper County sits in USDA Zone 5b. Radish grows reliably in zones 2a through 11b, so it's a good fit here.
Can Radish grow in Jasper County's climate?
Yes — Radish grows well in Jasper County's temperate climate. Jasper County averages a 158-day frost-free season, with last frost around May 2 and first frost around October 7.
Your Jasper County Garden Planner — Free
A 22-page printable planner built for Jasper County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.