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When to Plant Sunchoke in Pend Oreille 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.

Pend Oreille County, Washington is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is September 23, giving you a growing season of approximately 136 days.

At an elevation of 3,807 feet, Pend Oreille County receives approximately 13.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Sunchoke during the growing season. With low rainfall, drip irrigation is essential for growing Sunchoke successfully. Mulch heavily to conserve soil moisture.

Pend Oreille County, WA (Zone 5b) Short season
136 days
Last Spring Frost May 10
136 growing days
First Fall Frost September 23

Pend Oreille County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 15 🍅 Harvest: Sep 4 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: May 24 🍅 Harvest: Sep 13 – Nov 8
Safe Start (90%) ✗ May not fit
Transplant: Jun 14 🍅 Harvest: Oct 4 – Nov 29

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
0.4″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,080 gal / 100 sq ft
Sunchoke needs ~1,885 GDD — county provides 1,972 GDD Good fit

Sunchoke Planting Timeline โ€” Pend Oreille County, WA

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Harvest September 13 Sep 13 โ€“ Nov 8

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 Transplant Outdoors
July โ€”
August โ€”
September Harvest
October Harvest
November Harvest
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 5b

Growing Season

136 days

Growing Tips for Pend Oreille 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 Pend Oreille County, WA?

Pend Oreille County is in Zone 5b with an average last frost of May 10. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pend Oreille County, WA?

Pend Oreille County, Washington is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is September 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pend Oreille County gardeners in Zone 5b 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 Pend Oreille County, WA. Local conditions may vary. Last updated: April 2026.