How to Grow, Water and Take Care of Dahlias

Award-winning dahlia grower Dick Westfall shares some tips on how to grow and take care of those vibrant flowers.

Dick Westfall
Dick Westfall with the 'April Dawn' dahlia

Where can I grow dahlias?

Select an area of your yard with a minimum six hours of sun, preferably morning light and afternoon shade. Dahlias thrive in well-drained soil that has been enhanced with compost or manure.

Where can I buy dahlias?

Purchase quality tubers from online sources or growers specializing in dahlias. The Central Ohio Dahlia Society hosts an annual tuber sale in late April at Oakland Nurseries.

More:Two Dahlia Show Competitors Grow a 30-Year Bond

When should I plant dahlias?

In spring, jump-start the season by potting tubers in containers and covering them with potting soil. Water and keep them indoors in a warm place (65 to 75 degrees). The third week of May, transplant the potted dahlias outside in the garden. If you decide to skip the step of jump-starting tubers indoors, you can directly plant the tubers in the garden in early May. Dahlia plants are very frost sensitive, so be prepared to cover if necessary.

Dick Westfall and Jason Fairchild are avid, and award-winning, growers of dahlias in Marysville. (Photo by Tim Johnson)

When should I stake dahlias?

Stake plants with 5- to 7-foot stakes and fertilize them at the time of planting, then again when plants are 18–24 inches tall (around July 1). In late June or early July, once the soil has warmed, mulch around the plants with straw or grass clippings. This mulch layer plays an important role in cooling soil, conserving moisture and eliminating weeds.

How much should I water dahlias?

Dahlias need an adequate supply of moisture. Water at their bases as needed and water thoroughly.

When should I trim dahlias?

Once dahlias grow 2 to 3 sets of leaves, cut and remove the top to encourage branching. The denser and more compact the plants, the better the results will be. Continue to remove side buds to improve the size of the end blooms. You will reduce the number of blooms but increase bloom sizes.

'Cornel' dahlia

How do I control insect damage?

You may decide to tolerate minimal injury, or hand remove insects or treat plants with pesticides, as needed. If treating with pesticide, follow the package’s directions.

This story is from the May 2022 issue of Columbus Monthly.