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When to Plant Arugula in Gallatin 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.

Gallatin County, Illinois is in USDA Zone 6b. The average last spring frost is April 6 and the first fall frost is October 30, giving you a growing season of approximately 207 days.

At an elevation of 1,391 feet, Gallatin County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Arugula during the growing season.

Gallatin County, IL (Zone 6b) Long season
207 days
Last Spring Frost April 6
207 growing days
First Fall Frost October 30

Gallatin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Start indoors: Feb 23 Transplant: Mar 30 🍅 Harvest: May 4 – Jul 6
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: May 11 – Jul 13
Safe Start (90%) ✓ Fits season (117 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jul 24

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
0.3″/week
Watering frequency Only during dry spells
Season total 551 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 2,846 GDD Excellent fit

Arugula Planting Timeline โ€” Gallatin County, IL

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 โ€“ Mar 16
Transplant Outdoors April 6 Apr 6 โ€“ Apr 20
Direct Sow March 23 Mar 23 โ€“ Apr 13
Fall Sowing August 21 Aug 21 โ€“ Sep 4
Harvest May 11 May 11 โ€“ Jul 13

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
September Fall Sowing
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 6b

Growing Season

207 days

Growing Tips for Gallatin 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 Gallatin County, IL?

Gallatin County is in Zone 6b with an average last frost of April 6. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Gallatin County, IL?

Gallatin County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 6 and first fall frost is October 30.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Gallatin County gardeners in Zone 6b 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 Gallatin County, IL. Local conditions may vary. Last updated: April 2026.