When to plant Onion in Zone 2a
In Zone 2a, Onion: start seeds indoors around Mar 27–Apr 10; transplant outdoors around May 8–May 22. Expect to harvest around Aug 16–Aug 30.
| Step | When |
|---|---|
| Start seeds indoors | Mar 27 – Apr 10 |
| Transplant outdoors | May 8 – May 22 |
| Harvest | Aug 16 – Aug 30 |
Tip: Day-length sensitive — match the variety (long/short day) to your latitude for big bulbs.
Zone 2a averages a last spring frost around Jun 5 and a first fall frost around Aug 25. These are zone averages — look up your ZIP for your exact area.
See the full Zone 2a calendar in the tool →