Growing dahlia in zone 9b
In USDA zone 9b, the typical last spring frost is February 1 and the first fall frost is December 9. Here is when to plant dahlia against those dates.
Transplant outdoorsFebruary 1 to February 15
These are zone 9b averages
Computed from 2,081 ZIP codes in zone 9b. Your town's frost dates vary; enter your ZIP for dates built on your nearest weather station.
Get my exact datesUSDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service / Oregon State University PRISM Group. NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020. Planting windows for dahlia from Penn State Extension. Zone dates are medians; local conditions vary.