Blog

When to Plant Crosne in Pierce County, WA

Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

Pierce County, Washington is in USDA Zone 8a. The average last spring frost is April 13 and the first fall frost is October 30, giving you a growing season of approximately 200 days.

At an elevation of 168 feet, Pierce County receives approximately 48.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Crosne to ensure they mature before fall.

Pierce County, WA (Zone 8a) Long season
200 days
Last Spring Frost April 13
200 growing days
First Fall Frost October 30

Pierce County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 4 🍅 Harvest: Sep 5 – Nov 7
Recommended (50%) ✗ May not fit
Transplant: Apr 13 🍅 Harvest: Sep 14 – Nov 16
Safe Start (90%) ✗ May not fit
Transplant: May 16 🍅 Harvest: Oct 17 – Dec 19

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
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Crosne needs ~2,144 GDD — county provides 2,450 GDD Good fit

Crosne Planting Timeline โ€” Pierce County, WA

Crosne Planting Calendar

Activity When Date Range
Direct Sow March 30 Mar 30 โ€“ Apr 20
Fall Sowing August 21 Aug 21 โ€“ Sep 4
Harvest August 31 Aug 31 โ€“ Nov 2

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow
May โ€”
June โ€”
July โ€”
August Fall Sowing Harvest
September Fall Sowing Harvest
October Harvest
November Harvest
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

150โ€“200 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8a

Growing Season

200 days

Growing Tips for Pierce County

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Crosne in Pierce County, WA?

Pierce County is in Zone 8a with an average last frost of April 13. Plan your Crosne planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pierce County, WA?

Pierce County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 13 and first fall frost is October 30.

๐ŸŒฑ

Plan Your Garden with Confidence

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