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When to Plant Radish in Perkins County, SD

Perkins County, South Dakota Zone 4a April

Your April planting checklist for Perkins County, South Dakota

April is a pivotal month for Perkins County, South Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost October 2
Soil temp (4") 40°F
Watering Moderate
Pest pressure Low
Daylight 13.3 hrs
May prep starts now
  • Direct-sowing: radish

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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.

Perkins County, South Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is October 2, giving you a growing season of approximately 143 days.

At an elevation of 1,119 feet, Perkins County receives approximately 28.1 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Radish to ensure they mature before fall.

Perkins County, SD (Zone 4a) Short season
143 days
Last Spring Frost May 12
143 growing days
First Fall Frost October 2

Perkins County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Transplant: May 5 🍅 Harvest: Jun 2 – Jun 23
Recommended (50%) ✓ Fits season (94 days to spare)
Transplant: May 12 🍅 Harvest: Jun 9 – Jun 30
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: May 20 🍅 Harvest: Jun 17 – Jul 8

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 Perkins County

How your county's soil matches Radish's growing requirements.

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Perkins 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

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Radish

8
successive plantings in your 143-day season

Sow every 2.4 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 10.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.2" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 2.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.2" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 2.1" 0.1" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Perkins 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 needs ~306 GDD — county provides 1,537 GDD Excellent fit

Radish Planting Timeline — Perkins County, SD

Radish Planting Calendar

Activity When Date Range
Direct Sow May 5 May 5 – May 26
Harvest June 2 Jun 2 – Jun 23
Fall Sowing July 10 Jul 10 – Jul 24

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
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 4a

📆 Growing Season

143 days in Perkins County

Growing Tips for Radish in Perkins County

Direct sow Radish outdoors after May 12 in Perkins County when soil has warmed and frost danger has passed.

Your generous 143.0-day season in Perkins 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

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Perkins County, SD?

Perkins County is in Zone 4a with an average last frost of May 12. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Perkins County, SD?

Perkins County, South Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is October 2.

🌱

Your Perkins County Garden Planner — Free

A 24-page printable planner built for Perkins County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Perkins County, SD. Local conditions may vary. Last updated: April 2026.

Sources & credits

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