When to plant Onion in Zone 11a
In Zone 11a, Onion: start seeds indoors around Oct 23–Nov 6; transplant outdoors around Dec 4–Dec 18. Expect to harvest around Mar 14–Mar 28.
| Step | When |
|---|---|
| Start seeds indoors | Oct 23 – Nov 6 |
| Transplant outdoors | Dec 4 – Dec 18 |
| Harvest | Mar 14 – Mar 28 |
Tip: Day-length sensitive — match the variety (long/short day) to your latitude for big bulbs.
Zone 11a averages a last spring frost around Jan 1 and a first fall frost around Dec 31. These are zone averages — look up your ZIP for your exact area.
See the full Zone 11a calendar in the tool →