When to plant green beans in Detroit, Michigan
April 21 – May 5
Direct-sow outdoors · typical Detroit yearClimate basis: NOAA station Detroit City AP, MI (USW00014822), 6 mi (9 km) from downtown Detroit (ZCTA 48226 centroid), elevation 626 ft, on the 1991–2020 climate normals. Direct-sow green beans from approximately the dates above, anchored to the median last spring 32°F freeze (April 21). One year in ten still freezes after May 6.
The Detroit year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 6
Every method, with its sources
Direct-sow outdoors
Apr 21 – May 5UGA: plant as soon as the danger of frost has passed; UNH: plant seed in garden after last frost; Purdue: tender — plant after the average last frost. Point rule given a 14-day span. Anchored to the median last spring freeze (Apr 21). University of Georgia Cooperative Extension · University of New Hampshire Extension · Purdue University Extension
Start seeds indoors
Not calculatedBeans resent transplanting and are direct-seeded in the cited guides.
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 snap beans (about 55–65 days from seed; Penn State lists 60).
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 (3)
- University of Georgia Cooperative Extension: Home Garden Green Beans (Circular 1006) (accessed 2026-07-24)"Green beans are a warm season crop that can be planted as soon as the danger of frost has passed in the spring."
- University of New Hampshire Extension: Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet] (accessed 2026-07-24)Per-crop 'time from seed to transplant' and 'safe to set out in garden' relative to last frost.
- Purdue University Extension: Indiana Vegetable Planting Calendar (HO-186-W) (accessed 2026-07-24)Hardiness classes: hardy = plant 4-6 wk before last spring frost; semi-hardy = 2-4 wk before; tender = after average last frost; very tender = at least 2 wk after. Table 2: fall planting at least 4-8 wk before first fall frost.