When to plant onion in zone 4b
A planting schedule for onion in USDA hardiness zone 4b, where the typical last spring frost is around May 8, 2026 and the first fall frost around Oct 3, 2026. Dates are computed from NOAA frost normals for a representative location (Utica, MN) — your exact dates depend on your address.
Onion planting schedule for zone 4b
- Start seeds indoorsJan 30, 2026 – Sep 1, 2026
- Start hardening offApr 10, 2026 – Oct 20, 2026
- Transplant outdoorsApr 24, 2026 – Oct 27, 2026
Playing it safe with tender crops? Spring frost holds off until about May 22, 2026 in roughly 9 years out of 10.
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Onion in other zones
More crops for zone 4b
Frost dates are NOAA 1991–2020 climate normals for a representative location (Utica, MN) in zone 4b; your exact dates depend on your address. Schedules are guidance, not guarantees.