When to plant Sunflower in Zone 5b
In Zone 5b, Sunflower: direct sow outdoors around Apr 30–May 21. Expect to harvest around Jul 9–Jul 30.
| Step | When |
|---|---|
| Direct sow outdoors | Apr 30 – May 21 |
| Harvest | Jul 9 – Jul 30 |
Tip: Direct-sow once frost has passed; sow every two weeks for a long succession of blooms.
Zone 5b averages a last spring frost around Apr 30 and a first fall frost around Oct 5. These are zone averages — look up your ZIP for your exact area.
See the full Zone 5b calendar in the tool →