Crop dates by place

Onion Planting Dates by State and Region

Published onion planting windows for 1 places, with the source and the caveats you need before you use them.

Onion windows by place
Place	Planting	Harvest
New Hampshire	Start indoors: start seeds indoors 8-10 weeks before setting out; Transplanting: transplant 4 weeks before last frost

Calendar view

Onion calendar by place
Item	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
New Hampshire start indoors	Timing in table above
New Hampshire transplanting	Timing in table above

Frost-date caveat: ranges blur real differences inside a state or region. Use them to plan, then fit them to your last frost date, soil temperature and field conditions.

Related guides

Onion Planting Calendar: Sets vs. Seed
Onion Harvest and Curing Calendar

Last reviewed: November 2026. Source: UNH Extension - Growing Vegetables: When to Plant Your Vegetable Garden.