That's one reason these old-fashioned favorites have stood the test of time. "They were the 'it' flower from the mid to late 1800s and wildly popular again in the early 1900s," says Scott Kunst, owner of Old House Gardens, a mail-order nursery specializing in heirloom plants. They've been a staple of cutting gardens and cottage-style plantings ever since, thanks to their long-lasting blooms and easy-care nature. While spring is the time to plant their potato-like tubers, it's not too late to buy potted dahlias at garden centers to perk up your yard. Think of them as alternatives to end-of-season regulars, such as chrysanthemums and fall-flowering asters.
Shown: Five-foot-tall 'Lauren Michele' boasts waterlily blooms with pale lavender petals and dark undersides.