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When to Plant Radish in Otter Tail County, MN

Otter Tail County, Minnesota Zone 4a May

Otter Tail County, Minnesota gardeners: here's your May plan

A quick May briefing for Otter Tail County, Minnesota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 11
Avg. first frost September 28
Soil temp (4") 49°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Put radish seeds straight in the ground

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

A few tasks this May that'll pay off in June
  • First harvests: 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.

Otter Tail County, Minnesota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 28, giving you a growing season of approximately 140 days.

At an elevation of 571 feet, Otter Tail County receives approximately 40.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Radish to ensure they mature before fall.

Otter Tail County, MN (Zone 4a) Short season
140 days
Last Spring Frost May 11
140 growing days
First Fall Frost September 28

Otter Tail County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Transplant: Apr 28 🍅 Harvest: May 26 – Jun 16
Recommended (50%) ✓ Fits season (91 days to spare)
Transplant: May 11 🍅 Harvest: Jun 8 – Jun 29
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: May 21 🍅 Harvest: Jun 18 – Jul 9

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 Otter Tail County

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

Soil pH

Your soil pH (6.3–6.8) is within Radish's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Otter Tail 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 (5.2%) — 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 140-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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 1.9" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 5.7" 0" ✅ Rainfall sufficient
Jul 2.2" 5" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 3.4" 0" ❄️ Dormant
Nov 2.8" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Otter Tail 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 ~285 GDD — county provides 1,400 GDD Excellent fit

Radish Planting Timeline — Otter Tail County, MN

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 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

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 4a

📆 Growing Season

140 days in Otter Tail County

Growing Tips for Radish in Otter Tail County

Direct sow Radish outdoors after May 11 in Otter Tail County when soil has warmed and frost danger has passed.

Your generous 140.0-day season in Otter Tail 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 Otter Tail County, MN?

Otter Tail County is in Zone 4a 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 Otter Tail County, MN?

Otter Tail County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 28.

🌱

Your Otter Tail County Garden Planner — Free

A 24-page printable planner built for Otter Tail 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 Otter Tail County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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