Grow dahlias for gorgeous, colorful flowers that bloom from midsummer through autumn, when many plants are past their best! The tubers are planted in the ground in late spring. In colder zones, you do need to dig up and store the tubers in the fall if you wish to grow them as perennials (or, treat as annuals). Here’s how to plant, grow, and store dahlias.
Dahlia is a genus of tuberous plants that are members of the Asteraceae family; related species include the sunflower, daisy, chrysanthemum, and zinnia. They grow from small tubers planted in the spring. Picking a favorite dahlia is like going through a button box. As well as coming in a rainbow of colors, dahlia flowers can range in size from petite 2-inch lollipop-style pompoms to giant 15-inch “dinner plate” blooms. Most varieties grow 4 to 5 feet tall.
They are considered a tender perennial in cold regions of North America. They are reliably winter hardy in hardiness zones 8 to 11, though gardeners in zones 6 and 7 may have luck keeping them in the ground as well. In more northern zones, dahlias can either be treated as annuals or dug up and stored indoors for winter. (See what hardiness zone you’re in!)
Dahlias love moist, moderate climates. Though not well suited to extremely hot climates (such as southern Florida or Texas), dahlias brighten up any sunny garden with a growing season that’s at least 120 days long.