When to plant Radish in Johnson County, MO
Johnson County's climate puts the Radish spring window between March 30 and April 20. time plantings around the expected last-frost window for best survival. A second sowing from August 14 to August 28 extends the harvest into fall.
When to Plant Radish in Johnson County, MO
What to do in June
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Johnson County, Missouri.
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.
Johnson County, Missouri is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 23, giving you a growing season of approximately 193 days.
At an elevation of 1,218 feet, Johnson County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Radish during the growing season.
Johnson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Johnson County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Radish prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Johnson County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). 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 18 to harvest before frost.
For a dedicated fall crop, sow by Aug 14.
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 | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Johnson 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 — Johnson County, MO
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | April 27 | Apr 27 – May 18 |
| Fall Sowing | August 14 | Aug 14 – Aug 28 |
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: too_acidic
🗺️ USDA Zone
Zone 6b
📆 Growing Season
193 days in Johnson County
Growing Tips for Radish in Johnson County
Direct sow Radish outdoors after April 13 in Johnson County when soil has warmed and frost danger has passed.
Your generous 193.0-day season in Johnson 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 Johnson County, MO?
Johnson County is in Zone 6b with an average last frost of April 13. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, MO?
Johnson County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 23.
When should I plant Radish in Johnson County, MO?
In Johnson County, MO, plant Radish after the last frost (around April 13) and before the first frost (around October 23). Best results when soil holds above 50°F.
What growing zone is Johnson County, MO for Radish?
Johnson County sits in USDA Zone 6b. Radish grows reliably in zones 2a through 11b, so it's a good fit here.
Can Radish grow in Johnson County's climate?
Yes — Radish grows well in Johnson County's temperate climate. Johnson County averages a 193-day frost-free season, with last frost around April 13 and first frost around October 23.
Your Johnson County Garden Planner — Free
A 22-page printable planner built for Johnson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.