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When to Plant Radish in Marinette County, WI

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.

Marinette County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is October 1, giving you a growing season of approximately 136 days.

At an elevation of 782 feet, Marinette County receives approximately 31.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Radish to ensure they mature before fall.

Marinette County, WI (Zone 4b) Short season
136 days
Last Spring Frost May 18
136 growing days
First Fall Frost October 1

Marinette County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Transplant: May 11 🍅 Harvest: Jun 8 – Jun 29
Recommended (50%) ✓ Fits season (87 days to spare)
Transplant: May 18 🍅 Harvest: Jun 15 – Jul 6
Safe Start (90%) ✓ Fits season (87 days to spare)
Transplant: May 30 🍅 Harvest: Jun 27 – Jul 18

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 33 gal / 100 sq ft
Radish needs ~349 GDD — county provides 1,666 GDD Excellent fit

Radish Planting Timeline โ€” Marinette County, WI

Radish Planting Calendar

Activity When Date Range
Direct Sow May 11 May 11 โ€“ Jun 1
Fall Sowing July 9 Jul 9 โ€“ Jul 23
Harvest June 8 Jun 8 โ€“ Jun 29

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow Harvest
July Fall Sowing
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

22โ€“35 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

136 days

Growing Tips for Marinette County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Radish in Marinette County, WI?

Marinette County is in Zone 4b with an average last frost of May 18. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marinette County, WI?

Marinette County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marinette County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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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 Marinette County, WI. Local conditions may vary. Last updated: April 2026.