What to plant in March in zone 1b
22 crops to start indoors, direct sow, or transplant in March in USDA hardiness zone 1b. Typical last spring frost around May 29, 2026, first fall frost around Aug 28, 2026 — exact dates vary by location within the zone.
Zone 1b covers a lot of ground. Enter your ZIP for March dates from your nearest weather station and a month-by-month calendar:
Start indoors
Sow these under lights or on a windowsill now for transplants later.
Keep going
Timings use NOAA 1991–2020 climate normals for a representative location (ZIP 99745) in zone 1b, computed with the same engine as GardenDraft’s in-app schedule. Guidance, not guarantees — your exact dates depend on your address.