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When to Plant Arugula in Howard County, IN

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.

Howard County, Indiana is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 17, giving you a growing season of approximately 178 days.

At an elevation of 1,303 feet, Howard County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Arugula during the growing season.

Howard County, IN (Zone 5b) Moderate season
178 days
Last Spring Frost April 22
178 growing days
First Fall Frost October 17

Howard County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 20 – Jul 22
Recommended (50%) ✓ Fits season (80 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: May 27 – Jul 29
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 12 – Aug 14

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 22 gal / 100 sq ft
Arugula needs ~580 GDD — county provides 2,581 GDD Excellent fit

Arugula Planting Timeline โ€” Howard County, IN

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 8 Aug 8 โ€“ Aug 22
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 5b

Growing Season

178 days

Growing Tips for Howard 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 Howard County, IN?

Howard County is in Zone 5b 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 Howard County, IN?

Howard County, Indiana is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 17.

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Plan Your Garden with Confidence

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