Jenny Angel
Pompom. Cactus. Mignon. Waterlily. What seems like a random bunch of words could, in fact, make up a foursome in the New York Times Connections game—each one describes a distinct form of dahlia flower. (There are maybe a dozen forms in all; it depends on the expert you ask.)
These splendid flowers are members of the family Asteraceae, which includes several other late summer standouts, such as zinnias, sunflowers, and chrysanthemums. Dahlias come in every hue apart from blue. In 1846, a Scottish horticultural society announced a £2,000 reward to anyone who could develop a blue dahlia, a prize that remains unclaimed.
The hybridization efforts of dahlia breeders proceed at a frenetic pace, yielding hundreds of new varieties every year, some with blooms that are 8 to 12 inches across! Aside from roses, it’s hard to think of another flower that intrigues and delights gardeners as much as dahlias. The largest grower in the U.S., Swan Island Dahlias in Oregon, sends off hundreds of thousands of tubers in the spring shipping season.
Dahlias hail from Central America and, until the 1500s, were known only to the Aztecs and other Central American peoples, who used the leaves in medicines, the underground tubers as food, and the flowers in decorative arts. In the late 1700s, Spanish botanists dispersed the plants to Madrid and other parts of Europe, and dahlias have since made their way around the world.
Having evolved in warmer climes, dahlias don’t survive winters in New England. In late fall, gardeners must dig up the oblong tubers, which resemble chubby fingerling potatoes (and which some British call “chicken legs”) and store them until spring.
The peak time for dahlia blooms in Belmont is right about now in early September. Some local spots to view spectacular displays include the Victory Gardens at Rock Meadow and the community gardens east of the parking area at Habitat. If you are looking for local cut flowers, Sandra Curro, owner of the Underwood Greenhouses, periodically sells bouquets that include dahlias; look for them at her roadside stand on School Street, across from the St. Joseph’s Church parking lot.
On a recent gorgeous afternoon, Belmont gardener Carolyn Wood showed me her dahlias on Common Street and shared some pro tips for round-the-year care. She recommends cutting the frost-blackened foliage back nearly to the ground around mid-November, covering the stalks with foil, and leaving the plants in the ground for a couple of weeks.
As a Thanksgiving project, she pulls the tubers from the ground, shakes off the excess dirt, and packs them in vermiculite in an open box lined with newspaper and unlidded for air flow. Carolyn stores the tubers in a dry, dark, and cool (but not freezing) area of her basement, checking on them about once a month to remove any rotted or molding tubers and giving each container a light spritz of water. She plants the tubers around Mother’s Day (after all risk of frost has passed) and starts to see blooms in July, continuing through October. You can pot up tubers indoors to give the plants a head start. For those of us with limited time or storage space, dahlias can also be grown from seed.
Annie Helgason, another Belmont dahlia enthusiast, also starts a new crop each spring from saved tubers. Like Carolyn, she plants her dahlias in raised beds with chicken-wire framing to keep out rabbits, woodchucks, and the like. This is not always necessary, but it may bring you more success. Rabbit exclusion is especially important for the tender new shoots in spring. Annie stakes the stems using hefty tomato poles and self-attaching Velcro ribbon, made especially for gardening.
While not effort-free, growing dahlias returns huge dividends. Like the show-stopping finale that ends the fireworks on July 4th, these flowers close out the growing season with an extended technicolor display.
Jenny has been gardening in Belmont since 2001 and became a member of the Belmont Garden Club in 2019. From 2010 – 2013, she was the volunteer editor for the Belmont Farmers’ Market newsletter, “Roots & Sprouts.” As a Garden Gems columnist, she is excited to delve into Belmont’s horticultural history and current greenspaces and share tips from local experts on diverse aspects of gardening and related pursuits.