When to plant Onion in Zone 1b
In Zone 1b, Onion: start seeds indoors around Apr 1–Apr 15; transplant outdoors around May 13–May 27. Expect to harvest around Aug 21–Sep 4.
| Step | When |
|---|---|
| Start seeds indoors | Apr 1 – Apr 15 |
| Transplant outdoors | May 13 – May 27 |
| Harvest | Aug 21 – Sep 4 |
Tip: Day-length sensitive — match the variety (long/short day) to your latitude for big bulbs.
Zone 1b averages a last spring frost around Jun 10 and a first fall frost around Aug 20. These are zone averages — look up your ZIP for your exact area.
See the full Zone 1b calendar in the tool →