When to plant Onions in Connecticut
In spring, from Mar 1 – Apr 1 in Bridgeport to Apr 10 – May 1 in Torrington.
In fall, Sept 1 – Oct 15.
Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring | Fall |
|---|---|---|
| Ansonia | Mar 15 – Apr 10 | Spring-planted |
| Bridgeport | Mar 1 – Apr 1 | Sept 1 – Oct 15 |
| Bristol | Mar 15 – Apr 10 | Spring-planted |
| Danbury | Apr 1 – May 1 | Spring-planted |
| Derby | Mar 15 – Apr 10 | Spring-planted |
| Groton | Mar 15 – Apr 10 | Not listed |
| Hartford | Mar 15 – Apr 10 | Not listed |
| Meriden | Apr 1 – May 1 | Spring-planted |
| Middletown | Apr 1 – May 1 | Spring-planted |
| Milford | Mar 1 – Apr 1 | Sept 1 – Oct 15 |
| Naugatuck | Mar 15 – Apr 10 | Not listed |
| New Britain | Mar 15 – Apr 10 | Not listed |
| New Haven | Mar 15 – Apr 10 | Not listed |
| New London | Mar 15 – Apr 10 | Not listed |
| Norwalk | Mar 15 – Apr 10 | Spring-planted |
| Norwich | Mar 1 – Apr 1 | Spring-planted |
| Shelton | Mar 15 – Apr 10 | Spring-planted |
| Stamford | Mar 15 – Apr 10 | Spring-planted |
| Torrington | Apr 10 – May 1 | Spring-planted |
| Waterbury | Apr 1 – May 1 | Spring-planted |
| West Haven | Mar 15 – Apr 10 | Not listed |
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for onion plants.