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When to Plant Comfrey in Oregon

Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.

Oregon spans USDA hardiness zones 5a, 5b, 6a, 6b, 7a, 8a, 8b, 9a (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 Comfrey planting dates based on your local frost dates.

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

Comfrey Planting Calendar for Oregon

Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Transplant Outdoors May 2 May 2 – May 16
Harvest July 4 Jul 4 – Sep 12
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 April 25 Apr 25 – May 9
Harvest June 27 Jun 27 – Sep 5
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 17 Apr 17 – May 1
Harvest June 19 Jun 19 – Aug 28
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 10 Apr 10 – Apr 24
Harvest June 12 Jun 12 – Aug 21
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 1 Apr 1 – Apr 15
Harvest June 3 Jun 3 – Aug 12
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 15 Mar 15 – Mar 29
Harvest May 17 May 17 – Jul 26
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 4 Mar 4 – Mar 18
Harvest May 6 May 6 – Jul 15
Zone 9a ~303 day growing season · Full guide →

Last frost: February 10 · First frost: December 10 · 303 day season

Activity When Date Range
Transplant Outdoors February 17 Feb 17 – Mar 3
Harvest April 21 Apr 21 – Jun 30

Growing Tips for Oregon

Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.

Frequently Asked Questions

When should I plant Comfrey in Oregon?

Planting dates for Comfrey in Oregon depend on your USDA zone. Oregon spans zones 5a, 5b, 6a, 6b, 7a, 8a, 8b, 9a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Oregon for planting?

Oregon contains USDA hardiness zones 5a, 5b, 6a, 6b, 7a, 8a, 8b, 9a. 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.