PlantingWindowThe American Planting Almanac

When to plant radishes in Portland, Oregon

January 26 – February 9

Direct-sow 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. Direct-sow radishes 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 season≈ 280 daysmedian at 32°F
Hard freeze, 28°Jan 31 – Dec 20kills even hardy greens
USDA zone9a20 to 25°F winter low — not frost timing

The Portland year

Direct-sow outdoorsJan 26 – Feb 9
Fall plantingOct 6 – Nov 3
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Mar 21
Radishes in Portland · freeze context from Portland Kgw-tv, OR, 1991–2020 normals.

Every method, with its sources

Direct-sow outdoors

Jan 26 – Feb 9

Purdue: hardy — 4–6 weeks before the last frost; Penn State's earliest sowing Apr 1 (−30 days) is the later start and is used. Anchored to the median last spring freeze (Feb 25). Penn State Extension (York County Master Gardeners) · Purdue University Extension

Fall planting

Oct 6 – Nov 3

Purdue Table 2: plant fall radishes at least 4–8 weeks before the first fall frost. Anchored to the median first fall freeze (Dec 1). Purdue University Extension

Variety assumption: Assumes a spring type (about 25–35 days; Penn State lists 30).

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 (2)

Keep exploring

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