When to plant Sunflower in Zone 1a
In Zone 1a, Sunflower: direct sow outdoors around Jun 15–Jul 6. Expect to harvest around Aug 24–Sep 14.
| Step | When |
|---|---|
| Direct sow outdoors | Jun 15 – Jul 6 |
| Harvest | Aug 24 – Sep 14 |
Tip: Direct-sow once frost has passed; sow every two weeks for a long succession of blooms.
Zone 1a averages a last spring frost around Jun 15 and a first fall frost around Aug 15. These are zone averages — look up your ZIP for your exact area.
See the full Zone 1a calendar in the tool →