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When to Plant Arugula in Marinette County, WI

Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

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 Arugula 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 (39 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Jun 22 – Aug 24
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Jul 4 – Sep 5

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
Arugula needs ~490 GDD — county provides 1,666 GDD Excellent fit

Arugula Planting Timeline โ€” Marinette County, WI

Arugula Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 โ€“ Apr 20
Transplant Outdoors May 18 May 18 โ€“ Jun 1
Direct Sow May 11 May 11 โ€“ Jun 1
Fall Sowing July 9 Jul 9 โ€“ Jul 23
Harvest June 22 Jun 22 โ€“ Aug 24

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

136 days

Growing Tips for Marinette County

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Arugula in Marinette County, WI?

Marinette County is in Zone 4b with an average last frost of May 18. Plan your Arugula 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.