DAHLIAS rank among the most delightful of garden surprises. A brown potatolike tuber erupts into a flower factory on a stalk, staging a monthslong bloom show.
“Dahlias give you a larger variety of shapes, sizes and colors than other types of flowers,” says Nicholas Gitts, whose family owns Swan Island Dahlias in Canby, Oregon. Swan Island is the largest dahlia grower in the United States. “Dahlias also give you armloads of flowers over their blooming time—from late July through frost for most climates.”
Choose from lofty dahlias standing 5 feet or taller, or downsize with 12-inch dwarf types. Flower head sizes range from a dainty 2 inches across to the dinnerplate blooms that are nearly a foot wide. The flowers come with their own classifications, too: ball, pompon, cactus, anemone,…