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When to Plant Arugula in Skagit County, WA

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.

Skagit County, Washington is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is October 28, giving you a growing season of approximately 208 days.

At an elevation of 232 feet, Skagit County receives approximately 42.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Arugula during the growing season.

Skagit County, WA (Zone 8a) Long season
208 days
Last Spring Frost April 3
208 growing days
First Fall Frost October 28

Skagit County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: Apr 27 – Jun 29
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 8 – Jul 10
Safe Start (90%) ✓ Fits season (101 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 263 gal / 100 sq ft
Arugula needs ~700 GDD — county provides 3,640 GDD Excellent fit

Arugula Planting Timeline โ€” Skagit County, WA

Arugula Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 โ€“ Mar 13
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Direct Sow March 20 Mar 20 โ€“ Apr 10
Fall Sowing August 19 Aug 19 โ€“ Sep 2
Harvest May 8 May 8 โ€“ Jul 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
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 8a

Growing Season

208 days

Growing Tips for Skagit 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 Skagit County, WA?

Skagit County is in Zone 8a with an average last frost of April 3. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Skagit County, WA?

Skagit County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is October 28.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Skagit County gardeners in Zone 8a 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 Skagit County, WA. Local conditions may vary. Last updated: April 2026.