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When to Plant Arugula in Bureau County, IL

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.

Bureau County, Illinois is in USDA Zone 5a. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.

At an elevation of 613 feet, Bureau County receives approximately 34.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Arugula to ensure they mature before fall.

Bureau County, IL (Zone 5a) Moderate season
175 days
Last Spring Frost April 22
175 growing days
First Fall Frost October 14

Bureau County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jul 24
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: May 27 – Jul 29
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Aug 11

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 253 gal / 100 sq ft
Arugula needs ~520 GDD — county provides 2,275 GDD Excellent fit

Arugula Planting Timeline โ€” Bureau County, IL

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 8 Apr 8 โ€“ Apr 29
Fall Sowing August 5 Aug 5 โ€“ Aug 19
Harvest May 27 May 27 โ€“ Jul 29

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 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 5a

Growing Season

175 days

Growing Tips for Bureau 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 Bureau County, IL?

Bureau County is in Zone 5a with an average last frost of April 22. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bureau County, IL?

Bureau County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 22 and first fall frost is October 14.

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Plan Your Garden with Confidence

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