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When to Plant Arugula in Delta County, CO

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.

Delta County, Colorado is in USDA Zone 6a. The average last spring frost is May 1 and the first fall frost is October 8, giving you a growing season of approximately 160 days.

At an elevation of 4,470 feet, Delta County receives approximately 13.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Arugula during the growing season. With low rainfall, drip irrigation is essential for growing Arugula successfully. Mulch heavily to conserve soil moisture.

Delta County, CO (Zone 6a) Moderate season
160 days
Last Spring Frost May 1
160 growing days
First Fall Frost October 8

Delta County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Monthly Watering Guide for Arugula

Arugula needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Arugula Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jun 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Aug 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Sep 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Oct 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Delta County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Arugula Planting Timeline โ€” Delta County, CO

Arugula Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 โ€“ Apr 10
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 17 Apr 17 โ€“ May 8
Harvest June 5 Jun 5 โ€“ Aug 7
Fall Sowing July 30 Jul 30 โ€“ Aug 13

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 Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing 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

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

30โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

160 days in Delta County

Growing Tips for Delta 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Arugula in Delta County, CO?

Delta County is in Zone 6a with an average last frost of May 1. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Delta County, CO?

Delta County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 1 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

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