When to plant Dahlia in Zone 3b
In Zone 3b, Dahlia: start seeds indoors around Apr 22–May 6; transplant outdoors around May 27–Jun 3. Expect to harvest around Sep 4–Sep 11.
| Step | When |
|---|---|
| Start seeds indoors | Apr 22 – May 6 |
| Transplant outdoors | May 27 – Jun 3 |
| Harvest | Sep 4 – Sep 11 |
Tip: Plant tubers after frost. In cold zones, lift and store them indoors over winter.
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 →