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When to Plant Arugula in Linn County, MO

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.

Linn County, Missouri is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 20, giving you a growing season of approximately 186 days.

At an elevation of 880 feet, Linn County receives approximately 32.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Arugula during the growing season.

Linn County, MO (Zone 5b) Moderate season
186 days
Last Spring Frost April 17
186 growing days
First Fall Frost October 20

Linn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 16 – Jul 18
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jul 24
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 4 – Aug 6

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
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 533 gal / 100 sq ft
Drought risk

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

Arugula needs ~550 GDD — county provides 2,557 GDD Excellent fit

Arugula Planting Timeline โ€” Linn County, MO

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 โ€“ Mar 27
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Direct Sow April 3 Apr 3 โ€“ Apr 24
Fall Sowing August 11 Aug 11 โ€“ Aug 25
Harvest May 22 May 22 โ€“ Jul 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July Harvest
August Fall Sowing
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 5b

Growing Season

186 days

Growing Tips for Linn 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 Linn County, MO?

Linn County is in Zone 5b with an average last frost of April 17. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Linn County, MO?

Linn County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 20.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Linn County gardeners in Zone 5b 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 Linn County, MO. Local conditions may vary. Last updated: April 2026.