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When to Plant Arugula in Cass County, ND

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.

Cass County, North Dakota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.

At an elevation of 839 feet, Cass County receives approximately 33.1 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Arugula to ensure they mature before fall.

Cass County, ND (Zone 4a) Short season
144 days
Last Spring Frost May 11
144 growing days
First Fall Frost October 2

Cass County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Start indoors: Mar 21 Transplant: May 2 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17
Safe Start (90%) ✓ Fits season (48 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jun 26 – Aug 28

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 53 gal / 100 sq ft
Drought risk

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

Arugula needs ~400 GDD — county provides 1,440 GDD Excellent fit

Arugula Planting Timeline โ€” Cass County, ND

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Fall Sowing July 10 Jul 10 โ€“ Jul 24
Harvest June 15 Jun 15 โ€“ Aug 17

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
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 4a

Growing Season

144 days

Growing Tips for Cass 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 Cass County, ND?

Cass County is in Zone 4a with an average last frost of May 11. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cass County, ND?

Cass County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cass County gardeners in Zone 4a 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 Cass County, ND. Local conditions may vary. Last updated: April 2026.