Blog

When to Plant Arugula in Union 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.

Union County, Indiana is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 17, giving you a growing season of approximately 175 days.

At an elevation of 506 feet, Union County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Arugula during the growing season.

Union County, IN (Zone 6a) Moderate season
175 days
Last Spring Frost April 25
175 growing days
First Fall Frost October 17

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 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 21 Transplant: Apr 25 🍅 Harvest: May 30 – Aug 1
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jun 13 – Aug 15

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.

Soil Compatibility in Union County

How your county's soil matches Arugula's growing requirements.

Soil pH

Your soil pH (5.7โ€“7.2) overlaps with Arugula's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Union County is excellent for Arugula โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Arugula.

Organic Matter

Organic matter is excellent (4.1%) โ€” Arugula will thrive.

How to Plant Arugula

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Arugula

7
successive plantings in your 175-day season

Sow every 3.4 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Arugula needs ~700 GDD — county provides 3,062 GDD Excellent fit

Arugula Planting Timeline โ€” Union County, IN

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 โ€“ Apr 4
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 11 Apr 11 โ€“ May 2
Fall Sowing August 8 Aug 8 โ€“ Aug 22
Harvest May 30 May 30 โ€“ Aug 1

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 Direct Sow Harvest
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

30โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

175 days in Union County

Growing Tips for Arugula in Union County

Direct sow Arugula outdoors after April 25 in Union County when soil has warmed and frost danger has passed.

Your generous 175.0-day season in Union County allows multiple plantings of Arugula. Sow every 15.0 days for continuous harvest.

Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Union County, IN?

Union County is in Zone 6a with an average last frost of April 25. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, IN?

Union County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Union County, IN. Local conditions may vary. Last updated: April 2026.