When to plant Zinnia in Zone 3b
In Zone 3b, Zinnia: start seeds indoors around Apr 22–May 6; transplant outdoors around May 27–Jun 3; direct sow outdoors around May 20–Jun 3. Expect to harvest around Jul 19–Aug 2.
| Step | When |
|---|---|
| Start seeds indoors | Apr 22 – May 6 |
| Transplant outdoors | May 27 – Jun 3 |
| Direct sow outdoors | May 20 – Jun 3 |
| Harvest | Jul 19 – Aug 2 |
| Harvest | Jul 26 – Aug 2 |
Tip: A cut-flower workhorse. Direct-sow after frost and pinch young plants for more stems.
Zone 3b averages a last spring frost around May 20 and a first fall frost around Sep 12. These are zone averages — look up your ZIP for your exact area.
See the full Zone 3b calendar in the tool →