Dahlias

Bodacious Blooming Beauties

Michele MacKinnon

Dahlias were my gateway to the gardening world. They hooked me on gardening at the age of 12. The lush miracle that emerged from shriveled tubers I plunked into the ground after haphazard soil preparation left me enthralled. These days, a wave of new flower farmers across the United States has led to a tsunami of fans of all ages and passions.

 

A Brief Snapshot

Information abounds for novice growers. Dahlia societies are a good starting place. The Connecticut Dahlia Society hosts an August show at Elizabeth Park in West Hartford where these beauties may be seen firsthand. Grow them yourself with tubers purchased from societies, garden centers, and numerous mail order companies throughout the country.

Essential Tips for Success

  • Full sun is critical for these vigorous plants and blooming powerhouses.

  • Plant when soil temperatures reach 60 degrees, after all danger of frost has passed.

  • Dahlias require a long growing season so I start tubers indoors in pots. Use slightly damp, good quality potting soil, then plant outside after a few sets of leaves form.

  • Withhold water until growth appears, otherwise rotting could occur.

  • Pinch plants back to two or three sets of leaves. Really! It promotes additional branching which leads to more blooms, especially when using new single tubers.

Dahlias.jpg

Photo: Assorted sizes, styles and colors of dahlias grown by author

Photo credit: Michele MacKinnon

  • Despite advice to the contrary, I plant all tubers, regardless of size, in shallow holes. They like the warmer upper layer of soil. Hill them up with more soil later, if needed.

  • Add stakes or heavy duty tomato cages at planting time to support the heavy stems and flowers, particularly for larger varieties. Foliage soon hides the supports.

  • Protect tender shoots from slugs. Diatomaceous earth (a.k.a. kaolin clay) is one of the best organic deterrents. If slugs damage a tip, another will develop in a week or two.

  • Buds grow in groups of three. Remove side buds for straight, strong stems that hold up the resulting larger single flower, a practice among dahlia show competitors.

  • Tubers will grow in bulb crates or fabric “grow bags” with good results.

  • Dig up tubers one to two weeks after a killing frost to overwinter them. Store at 40 to 50 degrees F in a dry location. 

Check these links for information on overwintering and other advice:

American Dahlia Society

Connecticut Dahlia Society

Dahlias: Beautiful Varieties for Home & Garden by Naomi Slade and Georgianna Lane

The Plant Lover’s Guide to Dahlias by Andy Vernon

 

Michele MacKinnon, is a UCONN-Certified Advanced Master Gardener, garden educator and speaker, and Sierra Club Member.

 

Contact Michele MacKinnon for information.