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When to Plant Radish in Door County, WI

Door County, Wisconsin Zone 5b May

Door County, Wisconsin gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Door County, Wisconsin.

Avg. last frost May 11
Avg. first frost October 8
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Pick radish

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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.

Door County, Wisconsin is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is October 8, giving you a growing season of approximately 150 days.

At an elevation of 564 feet, Door County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Radish during the growing season.

Door County, WI (Zone 5b) Moderate season
150 days
Last Spring Frost May 11
150 growing days
First Fall Frost October 8

Door County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Transplant: May 5 🍅 Harvest: Jun 2 – Jun 23
Recommended (50%) ✓ Fits season (101 days to spare)
Transplant: May 11 🍅 Harvest: Jun 8 – Jun 29
Safe Start (90%) ✓ Fits season (103 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 Door County

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

Soil pH

Your soil pH (6.0–7.3) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Door 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 (4.7%) — Radish will thrive.

How to Plant Radish

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Radish

8
successive plantings in your 150-day season

Sow every 2.4 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Jul 30.

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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.7" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.6" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Door 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 ~435 GDD — county provides 2,287 GDD Excellent fit

Radish Planting Timeline — Door County, WI

Radish Planting Calendar

Activity When Date Range
Direct Sow April 27 Apr 27 – May 18
Harvest May 25 May 25 – Jun 15
Fall Sowing July 30 Jul 30 – Aug 13

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow Harvest
June Harvest
July Fall Sowing
August Fall Sowing
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 5b

📆 Growing Season

150 days in Door County

Growing Tips for Radish in Door County

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

Your generous 150.0-day season in Door 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 Door County, WI?

Door County is in Zone 5b 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 Door County, WI?

Door County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is October 8.

🌱

Your Door County Garden Planner — Free

A 24-page printable planner built for Door County (Zone 5b). 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 Door County, WI. Local conditions may vary. Last updated: May 2026.

Sources & credits

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