When to plant Thyme in Zone 4b
In Zone 4b, Thyme: start seeds indoors around Mar 15–Mar 29; transplant outdoors around May 10–May 24. Expect to harvest around Jul 29–Aug 12.
| Step | When |
|---|---|
| Start seeds indoors | Mar 15 – Mar 29 |
| Transplant outdoors | May 10 – May 24 |
| Harvest | Jul 29 – Aug 12 |
Tip: Perennial in most zones. Loves lean, well-drained soil — don't overwater or overfeed.
Zone 4b averages a last spring frost around May 10 and a first fall frost around Sep 22. These are zone averages — look up your ZIP for your exact area.
See the full Zone 4b calendar in the tool →