When to plant Cosmos in Zone 2a
In Zone 2a, Cosmos: direct sow outdoors around Jun 5–Jun 19. Expect to harvest around Aug 4–Aug 18.
| Step | When |
|---|---|
| Direct sow outdoors | Jun 5 – Jun 19 |
| Harvest | Aug 4 – Aug 18 |
Tip: Thrives on neglect — too-rich soil gives leaves at the expense of flowers.
Zone 2a averages a last spring frost around Jun 5 and a first fall frost around Aug 25. These are zone averages — look up your ZIP for your exact area.
See the full Zone 2a calendar in the tool →