Gardening 101: Growing Dahlias

Dahlias are the exuberance of a fall garden. Planted in mid-April then mostly forgotten, they show up and show off when the borders and the gardener need a boost. Mixed with other fall bloomers like sneezeweed, mountain mint, gaura, Joe Pye weed, rudbeckia, and anemones, dahlias take ordinary borders and make them extraordinary. And, they're pretty much pest and trouble free. (Jury is mixed on whether they serve as deer food. Please share your experience below). 

 Types of Dahlias

For a description of each type of dahlia, click on this quick read from American Dahlia Society. Listed below are the more recognizable forms of dahlias.  

  • Anemone

  • Ball or Pom Pom

  • Border

  • Catcus and Semi-catcus

  • Decorative

  • Dinnerplate

  • Mignon

  • Waterlily

Planting Dahlias, Growing Dahlias

Dahlias are hardy in zones 8-10. B.B. Barns sells dahlia tubers in spring. Dahlias are not part of your fall bulb planting (which we'll discuss in another post). They are considered a tender perennial, or summer bulb. The tubers look like potato tubers except dahlias only have eyes at the stem end of the tuber.

  • Plant dahlias in mid-April to early May, when the soil and air temperatures are warmer (60°).

  • Plant new tubers 1-2" deep with 1" of soil covering the sprouting tip.

  • Plant in full sun with good drainage, and a pH of 6.5-7.

  • Plant taller varieties outside of windy areas and where providing support will be easy. Use flower rings, stakes or plant near fences where stems can lean or be tied.

  • Fertilize with a low nitrogen fertilizer (5-10-10) a month after planting, then monthly after that. Do not overfeed.

  • Dig up in the fall. Dahlias are native to Mexico and Central America and while they will survive a mild winter here, they won't survive a harsh one. Dig up gently with a pitch fork and shake all the soil loose. Store in newspaper, sawdust or peat moss in a dry place for the winter. Douse with a bit of water once a month to avoid shriveling.

Growing Dahlias

  • Don't over-water. Like bulbs, the tubers need good drainage. Over-watering and poor drainage can cause bacterial or fungal problems in the soil. If the plant wilts, dig it up and discard the entire plant.

  • Borers and aphids are sometimes a problem. For aphids, Neem works well. For borers, cut off infected stems and destroy.

  • Always keep dahlias weeded, they don't like competition

More Information on Dahlias

If you'd like more information regarding dahlias, check out the links below.

Pretty Pictures of Dahlias

Thank you to Poppins Possies in Mills River for these dahlia pictures. They allowed me to stomp around their cut flower farm, which is presently loaded with dahlias, taking pictures one afternoon. (My job is the worst. :) These are definitely a feast for sore eyes. Click on each picture for the slideshow. 

 

Written by Cinthia Milner, garden coach, and blog writer.

B.B. Barns Garden Center serves all of Western North Carolina, upstate South Carolina and Tennessee.