When to Plant Onions in Vermont
In Vermont, the time to plant onions outside runs from Apr 1 – Apr 15 in Burlington to Apr 18 – May 2 in Barre. In Burlington, it's Apr 1 – Apr 15. The average last spring frost differs by about 2 weeks across the state (Apr 29 in Burlington, May 16 in Barre), so use the dates for the town nearest you.
Onions are cold-hardy. Plant sets or transplants early so they grow leaves before long summer days trigger bulbing.
- Start indoors: 10–12 weeks before the last frost.
- Plant outside: 2–4 weeks before the last frost.
Onions planting dates in Vermont by city
| City | Zone | Start indoors | Plant outside |
|---|---|---|---|
| Barre | 5a | Feb 21 – Mar 7 | Apr 18 – May 2 |
| Burlington | 5b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Essex Junction | 5a | Feb 7 – Feb 21 | Apr 4 – Apr 18 |
| Montpelier | 5a | Feb 10 – Feb 24 | Apr 7 – Apr 21 |
| Rutland | 5a | Feb 20 – Mar 6 | Apr 17 – May 1 |
| South Burlington | 5a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| St. Albans | 5a | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Winooski | 5a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Vermont, or the general guide to when to plant onions.
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