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When to Plant Sunchoke in Washington

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

Washington spans USDA hardiness zones 5b, 6a, 6b, 7a, 7b, 8a, 8b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Sunchoke planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Sunchoke Planting Calendar for Washington

Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Transplant Outdoors May 2 May 2 – May 16
Harvest August 22 Aug 22 – Oct 17
Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity When Date Range
Transplant Outdoors April 24 Apr 24 – May 8
Harvest August 14 Aug 14 – Oct 9
Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

Activity When Date Range
Transplant Outdoors April 17 Apr 17 – May 1
Harvest August 7 Aug 7 – Oct 2
Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity When Date Range
Transplant Outdoors April 8 Apr 8 – Apr 22
Harvest July 29 Jul 29 – Sep 23
Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity When Date Range
Transplant Outdoors April 1 Apr 1 – Apr 15
Harvest July 22 Jul 22 – Sep 16
Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

Activity When Date Range
Transplant Outdoors March 22 Mar 22 – Apr 5
Harvest July 12 Jul 12 – Sep 6
Zone 8b ~276 day growing season · Full guide →

Last frost: February 25 · First frost: November 28 · 276 day season

Activity When Date Range
Transplant Outdoors March 11 Mar 11 – Mar 25
Harvest July 1 Jul 1 – Aug 26

Growing Tips for Washington

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.

Frequently Asked Questions

When should I plant Sunchoke in Washington?

Planting dates for Sunchoke in Washington depend on your USDA zone. Washington spans zones 5b, 6a, 6b, 7a, 7b, 8a, 8b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Washington for planting?

Washington contains USDA hardiness zones 5b, 6a, 6b, 7a, 7b, 8a, 8b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.