When to Plant Radish in McPherson County, SD
Your May game plan for McPherson County, South Dakota
Here's what deserves your attention in McPherson County, South Dakota this month. Everything below is tailored to Zone 4b and timed around your local frost dates.
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Plant radish from seed, right in the garden
Your soil is 49°F — warm enough for these to germinate without babying.
Get ahead of June
- First harvests: 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.
McPherson County, South Dakota is in USDA Zone 4b. The average last spring frost is May 11 and the first fall frost is September 27, giving you a growing season of approximately 139 days.
At an elevation of 637 feet, McPherson County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 79°F, so choose short-season varieties of Radish to ensure they mature before fall.
McPherson County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.9
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 McPherson County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (6.7–7.9) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in McPherson County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Radish will thrive.
How to Plant Radish
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Aug 23 to harvest before frost.
For a dedicated fall crop, sow by Jul 05.
Plant 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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Oct | — | 1.5" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in McPherson 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 — McPherson County, SD
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | June 1 | Jun 1 – Jun 22 |
| Fall Sowing | July 5 | Jul 5 – Jul 19 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Harvest |
| July | Fall Sowing |
| August | — |
| 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_alkaline
🗺️ USDA Zone
Zone 4b
📆 Growing Season
139 days in McPherson County
Growing Tips for Radish in McPherson County
Direct sow Radish outdoors after May 11 in McPherson County when soil has warmed and frost danger has passed.
Your generous 139.0-day season in McPherson 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 McPherson County, SD?
McPherson County is in Zone 4b with an average last frost of May 11. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is McPherson County, SD?
McPherson County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 11 and first fall frost is September 27.
Your McPherson County Garden Planner — Free
A 24-page printable planner built for McPherson County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.