When to plant Dahlia
Showy tender perennials grown from tubers for spectacular late-summer blooms in every form and size. Plant after frost; staking the taller types is essential. In cold zones, lift the tubers after the first frost and store them dry and frost-free over winter.
Companions: A cutting-garden centrepiece; pairs well with zinnias and cosmos
How to grow Dahlia
Dahlia is usually started indoors and transplanted out, giving this tender crop the head start it needs. Give it full sun and space plants about 18 inches apart. It takes roughly 100 days from planting to its first harvest, so count that against your frost dates to be sure it can finish. Classic companions include a cutting-garden centrepiece; pairs well with zinnias and cosmos.
Grower's tip: Plant tubers after frost. In cold zones, lift and store them indoors over winter.
When to plant Dahlia by USDA zone
Timing shifts with your climate — the same dahlia goes in weeks earlier in a mild zone than a cold one. Find your zone below for its planting window, or open that zone's full calendar.
| Zone | When to plant |
|---|---|
| Zone 1a | Start seeds indoors May 18–Jun 1 Transplant outdoors Jun 22–Jun 29 |
| Zone 1b | Start seeds indoors May 13–May 27 Transplant outdoors Jun 17–Jun 24 |
| Zone 2a | Start seeds indoors May 8–May 22 Transplant outdoors Jun 12–Jun 19 |
| Zone 2b | Start seeds indoors May 2–May 16 Transplant outdoors Jun 6–Jun 13 |
| Zone 3a | Start seeds indoors Apr 27–May 11 Transplant outdoors Jun 1–Jun 8 |
| Zone 3b | Start seeds indoors Apr 22–May 6 Transplant outdoors May 27–Jun 3 |
| Zone 4a | Start seeds indoors Apr 17–May 1 Transplant outdoors May 22–May 29 |
| Zone 4b | Start seeds indoors Apr 12–Apr 26 Transplant outdoors May 17–May 24 |
| Zone 5a | Start seeds indoors Apr 7–Apr 21 Transplant outdoors May 12–May 19 |
| Zone 5b | Start seeds indoors Apr 2–Apr 16 Transplant outdoors May 7–May 14 |
| Zone 6a | Start seeds indoors Mar 24–Apr 7 Transplant outdoors Apr 28–May 5 |
| Zone 6b | Start seeds indoors Mar 18–Apr 1 Transplant outdoors Apr 22–Apr 29 |
| Zone 7a | Start seeds indoors Mar 10–Mar 24 Transplant outdoors Apr 14–Apr 21 |
| Zone 7b | Start seeds indoors Mar 4–Mar 18 Transplant outdoors Apr 8–Apr 15 |
| Zone 8a | Start seeds indoors Feb 22–Mar 8 Transplant outdoors Mar 29–Apr 5 |
| Zone 8b | Start seeds indoors Feb 15–Mar 1 Transplant outdoors Mar 22–Mar 29 |
| Zone 9a | Start seeds indoors Jan 31–Feb 14 Transplant outdoors Mar 7–Mar 14 |
| Zone 9b | Start seeds indoors Jan 18–Feb 1 Transplant outdoors Feb 22–Mar 1 |
| Zone 10a | Start seeds indoors Jan 3–Jan 17 Transplant outdoors Feb 7–Feb 14 |
| Zone 10b | Start seeds indoors Dec 18–Jan 1 Transplant outdoors Jan 22–Jan 29 |
| Zone 11a | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |
| Zone 11b | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |
| Zone 12a | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |
| Zone 12b | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |
| Zone 13a | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |
| Zone 13b | Start seeds indoors Dec 4–Dec 18 Transplant outdoors Jan 8–Jan 15 |