When to plant Dahlia in Zone 5b
In Zone 5b, Dahlia: start seeds indoors around Apr 2–Apr 16; transplant outdoors around May 7–May 14. Expect to harvest around Aug 15–Aug 22.
| Step | When |
|---|---|
| Start seeds indoors | Apr 2 – Apr 16 |
| Transplant outdoors | May 7 – May 14 |
| Harvest | Aug 15 – Aug 22 |
Tip: Plant tubers after frost. In cold zones, lift and store them indoors over winter.
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 →