Growing zucchini in zone 3b
(Zone 3b = an average winter low of -35°F to -30°F.)
In USDA zone 3b, the typical last spring frost is May 17 and the first fall frost is September 23. Here is when to plant zucchini against those dates.
Typical timing
Zone 3b planting schedule
Evidence trail
How these dates are built
Sprout applies the cited planting offsets to the typical zone 3b frost anchors. The result is a planning baseline for the zone, not a local weather forecast.
- USDA Plant Hardiness Zone Map, 2023USDA Agricultural Research Service / Oregon State University PRISM Group. Supports the USDA hardiness-zone band.
- U.S. Climate Normals 1991-2020NOAA National Centers for Environmental Information. Supports the median spring and fall freeze dates.
- Summer Squash (HGIC 1321)Clemson Cooperative Extension, Home & Garden Information Center. Supports direct-sowing timing (normalized) and days to maturity (direct).
Method note
Covers summer squash including zucchini. Direct-sow timing (after last frost, soil 60F), seed depth, thinned spacing and row spacing, days to maturity (about 55), soil pH (6.0 to 6.5), full sun, problem list. Water given only as a 6-inch soak depth, so inches per week is omitted.
These are zone 3b averages
Computed from 224 ZIP codes in zone 3b. Your town's frost dates vary; enter your ZIP for dates built on your nearest weather station.
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Put these dates to work
The plant profile covers spacing, light, water, soil, and source-backed timing details. The growing guide covers preparation, care, and harvest technique.