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When to Plant Radish in Lake County, MN

Lake County, Minnesota Zone 4a May

Top priorities for Lake County, Minnesota gardeners in May

Here's what deserves your attention in Lake County, Minnesota this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost June 1
Avg. first frost September 12
Soil temp (4") 51°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Seed radish outdoors

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

Coming up in June — start thinking about
  • First harvests: radish
  • Fall 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.

Lake County, Minnesota is in USDA Zone 4a. The average last spring frost is June 1 and the first fall frost is September 12, giving you a growing season of approximately 103 days.

At an elevation of 1,191 feet, Lake County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Radish to ensure they mature before fall.

Lake County, MN (Zone 4a) Short season
103 days
Last Spring Frost June 1
103 growing days
First Fall Frost September 12

Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Transplant: May 20 🍅 Harvest: Jun 17 – Jul 8
Recommended (50%) ✓ Fits season (54 days to spare)
Transplant: Jun 1 🍅 Harvest: Jun 29 – Jul 20
Safe Start (90%) ✓ Fits season (64 days to spare)
Transplant: Jun 18 🍅 Harvest: Jul 16 – Aug 6

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 Lake County

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

Soil pH

Your soil pH (5.9–6.8) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lake 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 (5.1%) — 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

5
successive plantings in your 103-day season

Sow every 2.4 weeks. Last sowing by Aug 08 to harvest before frost.

For a dedicated fall crop, sow by Jun 20.

Plant Water Budget

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

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 4.6" 0" ❄️ Dormant
Jun 2.2" 5.2" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 4.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.4" 0" ❄️ Dormant
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lake 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 1,107 GDD Excellent fit

Radish Planting Timeline — Lake County, MN

Radish Planting Calendar

Activity When Date Range
Direct Sow May 25 May 25 – Jun 15
Harvest June 22 Jun 22 – Jul 13
Fall Sowing June 20 Jun 20 – Jul 4

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow Fall Sowing Harvest
July Fall Sowing Harvest
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: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

103 days in Lake County

Growing Tips for Radish in Lake County

Direct sow Radish outdoors after June 01 in Lake County when soil has warmed and frost danger has passed.

Your generous 103.0-day season in Lake 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 Lake County, MN?

Lake County is in Zone 4a with an average last frost of June 1. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, MN?

Lake County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is June 1 and first fall frost is September 12.

🌱

Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lake 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.