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When to Plant Cardoon in Skagit County, WA

Cardoon is a large thistle relative of the artichoke, grown for its edible leaf stalks. It has dramatic silvery foliage and makes a striking ornamental as well.

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 Cardoon 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 (29 days to spare)
Transplant: Apr 6 🍅 Harvest: Aug 10 – Sep 21
Recommended (50%) ✓ Fits season (26 days to spare)
Transplant: Apr 17 🍅 Harvest: Aug 21 – Oct 2
Safe Start (90%) ✓ Fits season (17 days to spare)
Transplant: May 19 🍅 Harvest: Sep 22 – Nov 3

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 Skagit County

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

Soil pH

Your soil pH (5.6โ€“6.6) overlaps with Cardoon's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) โ€” Cardoon will thrive.

How to Plant Cardoon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

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
Cardoon needs ~2,362 GDD — county provides 3,640 GDD Excellent fit

Cardoon Planting Timeline โ€” Skagit County, WA

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Harvest August 21 Aug 21 โ€“ Oct 2

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

120โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

208 days in Skagit County

Growing Tips for Cardoon in Skagit County

Direct sow Cardoon outdoors after April 03 in Skagit County when soil has warmed and frost danger has passed.

Common pests for Cardoon in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Blanch stalks by wrapping with cardboard or tying leaves together 3-4 weeks before harvest. Provide deep, rich soil and consistent moisture. Protect from hard frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Cardoon in Skagit County, WA?

Skagit County is in Zone 8a with an average last frost of April 3. Plan your Cardoon 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.

๐ŸŒฑ

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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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 Skagit County, WA. Local conditions may vary. Last updated: April 2026.