When to plant lima bean in Seattle, Washington
March 13 – March 27
Direct-sow outdoors · typical Seattle yearClimate basis: NOAA station Seattle Boeing Fld, WA (USW00024234), 5 mi (8 km) from downtown Seattle (ZCTA 98104 centroid), elevation 20 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 (March 13). One year in ten still freezes after April 1.
The Seattle year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to Apr 1
Every method, with its sources
Direct-sow outdoors
Mar 13 – Mar 27Illinois 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 (Mar 13). Utah State University Extension
Start seeds indoors
Not calculatedThe cited extension guides do not time an indoor seed-starting window for this crop.
Transplant outdoors
Not calculatedThe cited extension guides do not time an outdoor transplanting window for this crop.
Fall planting
Not calculatedNo 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.
Crop rule sources (1)
- Utah State University Extension: Planting and Spacing — Legumes (Vegetable Guide) (accessed 2026-07-25)"Plant the cool-season legumes several weeks before and the warm-season legumes around the frost-free date for the location."