How To Grow Dahlias

Growing Dahlias in your Garden

Dahlias are some of the most timeless and best-loved flowers in the garden— as well as some of the showiest of cutting flowers! And on top of all of that, dahlias have such a wide range of colors, forms, and sizes that there is literally a dahlia for everyone and every garden or situation.

They are also fairly easy to grow. In fact, The American Dahlia Society insists that if you can grow tomatoes, you can grow dahlias! Here are some of the most common dahlia varieties, plus tips on how to grow these popular summer bloomers.

Big Beautiful Dahlias

Decorative: While it could be argued that all dahlias are decorative, this group of dahlias offers unusual colorations and styles as well as many heirloom varieties. Decorative dahlias typically have flat petals with either a distinct, even pattern or an irregular, random pattern.

Edge of Joy
American Sun
American Dawn
Hawaii

Dinnerplate: Living up to their name, Dinnerplate dahlias are the stunning giants of the dahlia world, growing up to 5’ tall (see staking tips below!) with flowers that are up to 10” across!

Striped Emory Paul
Otto’s Thrill
Alva’s Supreme
Jocondo

Waterlily: With rounded, broad petals and flattened centers, Waterlily dahlias usually grow 2-3’ tall but with surprisingly large, fully double blooms up to 5” across. Resembling actual waterlily flowers, they are excellent as cutting flowers in bouquets and arrangements.

Priceless Pink
Serkan
Apricot Desire
Caballero.

Cactus and Semi-Cactus: These blooms have tightly rolled, almost fringed petals that have a spiky or pointy appearance, hence their name. Semi-cactus dahlia petals have a bit of a broader base than their Cactus cousins, but both tend to require less staking than other dahlia varieties.

Nuit D’ete
Striped Vulcan

Dainty Darling Dahlias

Anemone-Flowered: Anemone dahlias have a center of tubular florets fringed with a few rows of open, rather than curled, petals. They typically grow 2-4’ tall, but some get as tall as 6 feet.

Edge of Joy
Fascination
Purple Haze

Mignon: Mignons have a single row of petals emerging from a contrasting center, creating a daisy-like appearance on a 2” diameter bloom. They are often compact — making them ideal for borders or containers — with dark-colored leaves.

Giselle
Bishop of Llandaff
Impression Famosa

Ball and Pom Pon: The rounded, globe-shaped blooms are 2-4” across and feature tightly rolled or rolled petals — with Pom Pons usually a bit smaller than the Ball varieties.

Boom Boom Yellow
Boom Boom Red
Franz Kafka
Mirella/Stolze Von Berlin

Compact: Also called “border dahlias,” these are smaller varieties, growing just 12-18” tall with blooms that are about 4” in diameter. And, because of their shorter height, they don’t require the staking that the taller varieties demand.

Monet
Art Deco
Melody Gypsy

Dahlia Growing Tips

Dahlias are tubers, and are planted in the spring after danger of frost has passed. Plant them about the same time as you plant your tomatoes, and up to mid-June.
Choose a site that has well-drained soil and part to full sun.
Plant the tuber several inches deep with the “eye” facing upwards. The eye is the narrower end of the tuber where the plant sprouts.
Planting more than one dahlia tuber? Plant them 2’ apart to give them each room to grow.
Add a stake at planting time, or use a tomato cage — dahlias tend to get big and need extra support. Tie the plant to the stake in several locations as it grows.
Water about 1” per week.

Dividing Dahlia Tubers

In planting zones 6 or lower after the first frost, dig up and store your dahlia tubers for the winter. In planting zones 7 or higher you can dig up your dahlias in the spring.

Cut back the dahlia foliage.
Dig up the dahlia tubers. Start by digging approximately 1 foot away from the dahlia plant, carefully loosening the soil. Once the soil is loosened, carefully lift the dahlia plant out of the ground, tubers have been known to snap off so handle them with care when removing them. Brush or shake off excess soil and inspect for viability.
Dividing dahlia tubers. Each dahlia division needs to have at least one shoot with an eye and a healthy tuber. The dahlia root clump consists of a large central tuber as well as small offshoot tubers. You can discard the central tuber it has done its job, it is the young offshoot tubers that are divided and kept. Also, the base of the stem where the growth eyes are located must be kept as well, it is the growth point for the stem in the next growing season.
Section dahlia tubers. Separate the dahlia clump into sections, each section should include a part of the stem base with an eye and one or more offset tubers. Carefully examine the clump, and using a sharp knife cut sections that include one shoot and a set of roots.
Dry dahlia tubers. If you are storing for the winter allow the sections to dry out slightly in the open air before storing. When the tubers begin to wrinkle, they are ready to be stored.
Propagate dahlias. In spring dahlias can also be propagated by taking basal cuttings. Each dahlia tuber can give you four to five new plants that will flower come summer.

Cottage Garden Tour: Spring Flowers

In this video Kim, a long-time flower & hobby gardener in Washington Zone 8b, shows us around her waterfront cottage garden, spring flowers. and greenhouse. She teaches us some fun cut flower gardening tips including how to divide dahlias.

Whether your garden is big or small, make the most of your space with these tips and watch the full Cottage Garden Tour: Spring Flowers video on the Kellogg Garden Youtube Channel.