When to plant chives in Portland, Oregon

February 25 – March 11

Transplant outdoors · typical Portland year

Climate basis: NOAA station Portland Kgw-tv, OR (USC00356749), 1 mi (1 km) from downtown Portland (ZCTA 97204 centroid), elevation 159 ft, on the 1991–2020 climate normals. Transplant chives outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (February 25). One year in ten still freezes after March 21.

Last spring freezeFebruary 251-in-10 after Mar 21
First fall freezeDecember 11-in-10 before Nov 10
Frost-free season280 daysmedian at 32°F
Hard freeze, 28°Jan 31Dec 20kills even hardy greens
USDA zone9a20 to 25°F winter low not frost timing

The Portland year

Start seeds indoorsDec 31 – Jan 14
Transplant outdoorsFeb 25 – Mar 11
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Mar 21
Chives in Portland · freeze context from Portland Kgw-tv, OR, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Dec 31 – Jan 14

Wisconsin Horticulture starts chive seed indoors before the last frost date for planting out after frost danger, but says only 'a few weeks'; USU Extension fixes the lead time at 6 to 8 weeks of growth before garden planting, so sowing runs 8 to 6 weeks before the last spring freeze. Anchored to the median last spring freeze (Feb 25). University of Minnesota Extension · University of Wisconsin-Madison Division of Extension, Wisconsin Horticulture · Utah State University Extension

Transplant outdoors

Feb 25 – Mar 11

UMN Extension says the easiest and most successful way to grow chives is planting rooted clumps in spring after frost danger has passed, and Wisconsin Horticulture likewise puts indoor-started plants out after the danger of frost is past; both agree, so the window opens at the last spring freeze. Anchored to the median last spring freeze (Feb 25). University of Minnesota Extension · University of Wisconsin-Madison Division of Extension, Wisconsin Horticulture · Utah State University Extension

Variety assumption: Wisconsin Horticulture warns that direct-seeded chives give little or no harvest the first year, so rooted clumps or indoor-started transplants are the practical route.

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

This week, not a typical year:
Crop rule sources (3)

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