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When to Plant Radish in Haakon County, SD

Haakon County, South Dakota Zone 4b April

Your April planting checklist for Haakon County, South Dakota

Here's what deserves your attention in Haakon County, South Dakota this month. Everything below is tailored to Zone 4b and timed around your local frost dates.

Avg. last frost May 14
Avg. first frost September 28
Soil temp (4") 39°F
Watering High
Pest pressure Low
Daylight 13.2 hrs
Get ahead of May
  • 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.

Haakon County, South Dakota is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.

At an elevation of 1,097 feet, Haakon County receives approximately 22.5 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.

Haakon County, SD (Zone 4b) Short season
137 days
Last Spring Frost May 14
137 growing days
First Fall Frost September 28
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Haakon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Transplant: May 9 🍅 Harvest: Jun 6 – Jun 27
Recommended (50%) ✓ Fits season (88 days to spare)
Transplant: May 14 🍅 Harvest: Jun 11 – Jul 2
Safe Start (90%) ✓ Fits season (85 days to spare)
Transplant: May 26 🍅 Harvest: Jun 23 – Jul 14

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 Haakon County

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

Soil pH

Your soil pH (6.5–7.5) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Haakon County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is excellent (4.1%) — 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

7
successive plantings in your 137-day season

Sow every 2.4 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 06.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.2" 2.6" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 1.9" 0.3" 💧 Light watering
Aug 2.2" 2.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.8" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Haakon 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 1,472 GDD Excellent fit

Radish Planting Timeline — Haakon County, SD

Radish Planting Calendar

Activity When Date Range
Direct Sow May 7 May 7 – May 28
Harvest June 4 Jun 4 – Jun 25
Fall Sowing July 6 Jul 6 – Jul 20

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
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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 4b

📆 Growing Season

137 days in Haakon County

Growing Tips for Radish in Haakon County

Direct sow Radish outdoors after May 14 in Haakon County when soil has warmed and frost danger has passed.

Your generous 137.0-day season in Haakon 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 Haakon County, SD?

Haakon County is in Zone 4b with an average last frost of May 14. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Haakon County, SD?

Haakon County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 28.

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Your Haakon County Garden Planner — Free

A 24-page printable planner built for Haakon 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.

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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 Haakon County, SD. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.