When to plant lima bean in Portland, Oregon

February 25 – March 11

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 lima bean 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

Direct-sow outdoorsFeb 25 – Mar 11
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Mar 21
Lima Bean in Portland · freeze context from Portland Kgw-tv, OR, 1991–2020 normals.

Every method, with its sources

Direct-sow outdoors

Feb 25 – Mar 11

Illinois Extension's Hort Answers entry for Phaseolus vulgaris and P. lunatus says beans should be planted after all danger of frost is past, and Utah State's legume planting guide places the warm-season legumes — which it lists as snap or dry beans and lima bean — around the frost-free date; both point to the last-frost date itself, so the point rule opens the window at the anchor and runs the standard 14 days. Illinois' allowance for planting a week to 10 days early in warm soil was rejected as the earlier-starting, less frost-conservative reading. Anchored to the median last spring freeze (Feb 25). Utah State University Extension

Start seeds indoors

Not calculated

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

Transplant outdoors

Not calculated

The cited extension guides do not time an outdoor transplanting window for this crop.

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: Assumes bush or pole lima sown directly in place; Maryland Extension notes limas need soil at 65°F for five days to germinate well, so gardeners in a cold spring should plant toward the later end of the window rather than at its opening.

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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