When you’re the king of the garden, looks are everything. From regal to wild, mini to gigantic, dahlias are the flower that will win your heart.
Although pompons add flair and showoffs are stellar, the secret to staying royal? Size matters.
“Everybody wants the big ones,” says Steve Bressler, past president of the Colorado Dahlia Society. “At our April tuber sale, 90 percent of the customers go for the big bloom table. But dahlias are a remarkable flower; they come in all sizes, shapes, and color.”
Bressler plants 150 dahlias yearly in his Lakewood yard and has a hard time choosing favorites. “It depends on the year you ask me and what day it is,” he said. “I’m not a huge grower; I just have a little suburban yard. We started out with just a dozen, but now half the backyard is given over to dahlias.”
If casual, wildly relaxed is your style, try cactus-bloom dahlias, whose tousled flowers have corkscrewing petals. Like a permanent case of “bed head,” their brightly colored cowlicks provide dramatic texture to the garden. Novelty laciniated dahlias have petals that split and twist at the end, giving the flower a fireworks-like appeal.
Many dahlias offer bicolored blooms in rich, saturated tones, making them a coveted part of the late- summer garden. Growing from 3 to 6 feet tall, they stare you in the eye with blossoms the size of your head.
“The perception is dahlias are hard to grow, but they’re not,” says Calvin Cook, owner of Arrowhead dahlias in Platteville. “Plant them in the same conditions you would a tomato, and if you don’t want to dig them up in fall, treat them like an annual.”
Cook grows 10,000 dahlias on 3 acres. He fell in love with the plants as a child.
“They’re a fall flower that puts on a show in August and September. Everybody who tries them loves them,” he said.
For success, follow four basic steps: topping, supporting, disbudding, and deadheading.
Plant after danger of frost in a full to part-sun area, leaving the eye of the tuber — the tapered growing tip — pointed up.
Provide support by staking or use a method developed by society member Don McAllister: cut off the legs of a tomato cage, flip it over and put the large end of the cage over the dahlia. Bend the clipped-off legs into U-shaped pins and use them to secure the cage to the ground.
Most dahlias grow in well-drained soil, and although they need a little extra water just as they begin to bloom, they don’t like it soggy. Give them high-nitrogen fertilizer regularly through the middle of the season.
And top them. Dahlias put up a stem with a single flower; encourage branching to get more blooms. Pinch them back when young, nipping off large-flowered plants (8-inch blossoms or larger) once they’ve got four sets of leaves; medium plants (6- to 8-inch blossoms) at six sets of leaves; and those with smaller blooms at eight sets of leaves.
About a month after you top the dahlia, the first buds form. Dahlias form buds in triples, but if you leave them, the flowers will be small. Remove the two outside buds, leaving the center one to become a single, whopping-big blossom. Deadhead flowers once they’re spent to help your dahlia continue the show until frost.
Pests for this plant are few, with the exception of random passersby who might snip the bloom to take it home with them.
Dahlias need to be dug up in the fall and stored over the winter. To help them harden off for this, cut off the fertilizer six to eight weeks before the end of the season.
Read Carol O’Meara on her blog
More dahlia information
Need some extra help? Here’s where to look:
Arrowhead Dahlias, , for photos and tubers.
The Colorado Dahlia Society, , for shows, events, and advice.
The American Dahlia Society, , for photos, articles, and links.
