When to plant asparagus in Portland, Oregon

January 14 – January 28

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. Plant asparagus crowns 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

Transplant outdoorsJan 14 – Jan 28
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Mar 21
Asparagus in Portland · freeze context from Portland Kgw-tv, OR, 1991–2020 normals.

Every method, with its sources

Transplant outdoors

Jan 14 – Jan 28

Purdue: hardy — plant crowns 4–6 weeks before the last spring frost. Anchored to the median last spring freeze (Feb 25). Purdue University Extension

Start seeds indoors

Not calculated

The cited extension guides do not time an indoor seed-starting window for this crop.

Direct-sow outdoors

Not calculated

Home plantings start from 1-year crowns; seed-started asparagus adds a year and is not timed by the cited guide.

Fall planting

Not calculated

No source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.

Variety assumption: A long-lived perennial; do not harvest the planting year, lightly the second year, fully from the third.

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 (1)

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