Available in thousands (really) of variations, dahlias bloom well into fall—and with just a little post-frost work, can survive for an encore come spring.

By Hannah Agran
Dahlias

One of the world's most diverse flower species, dahlias dazzle from June or July until October.

Pros often classify dahlias by shape. For example, these orbs of compact florets fall under the miniature ball or pompon categories. Photo: Brittany Wright

Here's how to get the most out of the growing season.

1 Choose a spot Dahlias grow best in moist, well-drained soil with full sun. Depending on the variety, they will reach between 1 and 8 feet tall.

2 Go shopping Some growers sell plants, but for the best variety and prices, order tubers (similar to bulbs) at an online resource such as dahlias.com.

3​ Plant the tubers Well after last frost (late May or early June), plant tubers and water them. Ideally, when plants emerge, mulch with 2 inches of hay or compost to keep roots cool.

4 Keep them tidy When plants reach 6 inches, remove all but the strongest stem. When plants reach 1 foot and have leaves, trim tops to encourage branching. Stake tall plants or use cages.

Photo: Laurie Black.

Great clips The more you harvest, the more dahlias bloom, so fill vases and deadhead often. Avoid cutting under midday sun.

Photo: Blaine Moats

Three steps to saving your dahlias for next year:

1 Dig In cold zones like the Midwest, dig up tubers a week or so after the first hard frost. Cut stalks to 5 inches. Let tubers dry one to two days out of the sun. Rinse and let dry fully. Label with a marker.

2 Divide Divide big clumps in half through the stalk. Place in a Styrofoam box or crate. Cover with vermiculite or a combo of newspaper and pine shavings. Store in a cool spot, such as a basement. (Check occasionally; mist lightly if shriveling.)

3 Divide again In spring, further divide clumps into small ones or individual tubers to make new plants. Make sure each cluster or tuber has an "eye," a bud on the knobby end that will sprout a stem.

The legend of dahlias: ​

How a handful of tubers crossed the Atlantic in a ship's hold and changed flower history. Centuries ago, a few species of dahlia grew wild in Mexico. (Aztecs used them for food and medicine.) In 1789, botanists sent dahlia tubers to the Royal Gardens of Madrid for scientific study. Two centuries of eager hybridization later, gardeners can choose from some 50,000 varieties-and they all descend from those original Mexican ancestors.

Photo: Laurie Black

"They command the spotlight, and their variety is amazing. I saw a bumper sticker once that read Celebrate Diversity: Grow Dahlias." - Lisa Ringer, owner of Two Pony Gardens in Long Lake, Minnesota

To learn more about Two Pony Gardens, go to midwestliving.com/dahlias

Advertisement