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When to Plant Sunchoke in Clallam County, WA

Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Clallam County, Washington is in USDA Zone 8a. The average last spring frost is April 23 and the first fall frost is October 26, giving you a growing season of approximately 186 days.

At an elevation of 194 feet, Clallam County receives approximately 54.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Sunchoke to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunchoke root diseases.

Clallam County, WA (Zone 8a) Moderate season
186 days
Last Spring Frost April 23
186 growing days
First Fall Frost October 26

Clallam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Transplant: Apr 28 🍅 Harvest: Aug 18 – Oct 13
Recommended (50%) ✓ Fits season (4 days to spare)
Transplant: May 7 🍅 Harvest: Aug 27 – Oct 22
Safe Start (90%) ✓ Fits season (2 days to spare)
Transplant: May 23 🍅 Harvest: Sep 12 – Nov 7

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunchoke needs ~1,592 GDD — county provides 2,278 GDD Excellent fit

Sunchoke Planting Timeline โ€” Clallam County, WA

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 โ€“ May 21
Harvest August 27 Aug 27 โ€“ Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

110โ€“150 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8a

Growing Season

186 days

Growing Tips for Clallam County

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunchoke in Clallam County, WA?

Clallam County is in Zone 8a with an average last frost of April 23. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clallam County, WA?

Clallam County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 23 and first fall frost is October 26.

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Plan Your Garden with Confidence

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