When to plant Basil in Zone 4b
In Zone 4b, Basil: start seeds indoors around Mar 29–Apr 12; transplant outdoors around May 17–May 31. Expect to harvest around Jul 16–Jul 30.
| Step | When |
|---|---|
| Start seeds indoors | Mar 29 – Apr 12 |
| Transplant outdoors | May 17 – May 31 |
| Harvest | Jul 16 – Jul 30 |
Tip: Extremely frost-sensitive. Keep indoors until nights are reliably warm, then pinch often.
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 →