When to plant Cosmos in Zone 2b
In Zone 2b, Cosmos: direct sow outdoors around May 30–Jun 13. Expect to harvest around Jul 29–Aug 12.
| Step | When |
|---|---|
| Direct sow outdoors | May 30 – Jun 13 |
| Harvest | Jul 29 – Aug 12 |
Tip: Thrives on neglect — too-rich soil gives leaves at the expense of flowers.
Zone 2b averages a last spring frost around May 30 and a first fall frost around Sep 1. These are zone averages — look up your ZIP for your exact area.
See the full Zone 2b calendar in the tool →