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When to Plant Arugula in Brown County, MN

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.

Brown County, Minnesota is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 1,199 feet, Brown County receives approximately 31.8 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.

Brown County, MN (Zone 4b) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7

Brown County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Mar 13 Transplant: Apr 24 🍅 Harvest: May 29 – Jul 31
Recommended (50%) ✓ Fits season (62 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Jun 4 – Aug 6
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jun 19 – Aug 21

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 282 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Arugula needs ~490 GDD — county provides 1,960 GDD Excellent fit

Arugula Planting Timeline โ€” Brown County, MN

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 23 Apr 23 โ€“ May 14
Fall Sowing July 15 Jul 15 โ€“ Jul 29
Harvest June 4 Jun 4 โ€“ Aug 6

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June 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

160 days

Growing Tips for Brown 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 Brown County, MN?

Brown County is in Zone 4b with an average last frost of April 30. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Brown County, MN?

Brown County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Brown 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 Brown County, MN. Local conditions may vary. Last updated: April 2026.