Dahlias and Herbs

Tall Dahlias

• Tall to medium dahlias, like 36-inch "Bishop of Llandaff," hardy in USDA zones 9 through 11, work well in the middle to back of mixed borders or dedicated herb gardens. Intermingled with herbs like 24-inch "Black Adder" hummingbird mint (Agastache "Black Adder"), hardy in USDA zones 8 through 11; tall dahlias can provide late summer blooms that contrast with the foliage of low-growing, earlier-blooming herbs like English thyme (Thymus vulgaris), hardy in USDA zones 5 through 9 and "Kent Beauty" oregano (Oreganum "Kent Beauty"), hardy in USDA zones 6 through 9.

Shorter Dahlias

• Shorter dahlias, like the dwarf bedding variety "Ellen Huston," with orange flowers and bronze leaves, add flower and foliage color that complements green-leafed herbs of similar stature like chives (Allium schoenoprasum), hardy in USDA zones 5 through 11. They also add visual interest when paired with scented leaf geraniums like "Royal Oak" (Pelargonium "Royal Oak") whose flowers are small, but whose scented leaves add a dimension to the color provided by the relatively scentless dahlias. The geranium's ruffled foliage also contrasts with the dahlia leaves. "Royal Oak" is hardy in USDA zones 10 through 11.

Container Combinations

• Large containers, like half whiskey barrels, are perfect for dahlia/herb mixes. A giant dinner plate dahlia, like 42-inch "Hamart Gold," hardy in USDA zones 9 through 11, might serve as a tall focal point, surrounded by several 12- to 16-inch-tall, lemon-scented "Mabel Gray" geraniums (Pelargonium "Mable Gray"), hardy in USDA zones 10 through 11. If the container has sufficient room, use a trailing herb, like "Well Sweep Gold" rosemary (Rosmarinus officinalis "Well Sweep Gold"), hardy in USDA zones 7 through 10, to cascade over the sides of the container.

Culture

• In spring, start dahlia tubers indoors a few weeks before the last frost day for the area. Start annual herbs from seed at the same time. Wait until all danger of frost has passed to plant both dahlias and sun-loving herbs in sunny, well-drained locations. Drainage is essential, especially to dahlias, as damp clay soil will rot the tubers. Insert stakes next to taller dahlia varieties while doing the initial planting in spring. Harvest culinary herb leaves regularly. When dahlias begin to bloom in late summer, deadhead spent flowers to ensure repeat blooming.