Dahlias and Gladiolas: What to do with them now?

by Lea Anne Moran | November 7, 2014

Dahlias and gladiolas are beloved plants, used often by Beatrix Farrand for late season color in her garden designs.

In Hill-Stead’s Sunken Garden, Farrand used the Alpen Cherub dahlia, a tall ‘collarette’ variety with rounded white petals. It is a spectacular addition to the late season garden that sparkles with its purple, blue, and white fall color scheme.

Dahlia 'Alpen Cherub' is a tall white-flowering collarette variety.
Dahlia ‘Alpen Cherub’ is a tall white-flowering collarette variety.

There are two types of gladiolas in the Sunken Garden, Gladiolus ‘White Goddess’, a large flowering white variety, and G. dalenii ‘Carolina primrose’ (a soft yellow) and ‘Boone’ (a lovely peach).

Gladiolus 'White Goddess', a large flowering white variety
Gladiolus dalenii ‘Boone’, one of the heirloom varieties in the Sunken Garden, designed by Beatrix Farrand c. 1920

At the end of each gardening year, usually once the garden has been hit by frost, the dahlia tubers and gladiolus corms are gently dug and stored for replanting the following season. It’s easy to do, as long as you know how to do it and have the right conditions. Here are a few tips on digging and storing dahlias and glads, if you would like to try it yourself. The process is similar, but will be described separately here.

Autumn in the Sunken Garden at the Hill-Stead Museum in Farmington. Photo by Bill Watson.

Dalias

Digging the Dahlia

After a killing frost, cut the stem and leaves to about six inches, and gently dig the tubers with a spade or pitchfork. Leave lots of room when you dig being careful not to cut the tubers or break them once you dig them up. Remove the dirt gently, and wash them to remove the remaining dirt. Let the tubers air dry in a protected spot, like a garage or shed.

Storing for Winter

Store your tubers in a crate or cardboard box that has been filled with a storage medium, such as peat moss, sand, or even shredded paper. Some people use paper from the paper shredder, or newspaper torn into strips. First, line the container with several sheets of newspaper. Then put the storage material in the bottom and gently lay your dried tubers on top. Add another layer of storage material and repeat until the box is full.

Do not use plastic bags or containers. The tubers need air circulation and this prohibits that.

Store in a cool, dry spot with a temperature that is between 40 and 50 degrees F. A cool basement or fruit cellar is ideal. A garage might be good if it is attached and you watch the temperature during the winter. If the temperature is too warm they will shrivel and wrinkle, and if it’s too cold, they will freeze. It’s always best to check them once a month through the winter months to make sure the temperatures are safe for them.

Gladiolus ‘White Goddess’, a large-flowering white heirloom variety in Hill-Stead’s Sunken Garden.

Gladioli

Digging the Gladioli

About four to six weeks after the last bloom or once the leaves turn yellow dig the gladioli from the ground. You’ll see lots of tiny cormlets, which can be removed from the corm, saved and planted next spring. Cut the stalk to about one-half inch. Wash the corms, and lay out to dry for two to three weeks to be sure there is no moisture that might cause disease. Leave the husk on to help retain moisture.

Storing the Corms

Once the corms are dry, store in a mesh bag, nylon stocking or basket. It’s recommended to spray corms with an all-purpose fungicide before being stored. Store the basket or hang the bag in a cool, well-ventilated location for winter, at a temperature of 35 to 45 degrees.

 ~ Lea Anne Moran, Garden Manager

Hill-Stead Museum

The Hill-Stead Museum is located at 35 Mountain Avenue in Farmington, CT, and is open Tuesday through Sunday 10:00 to 4:00. For more information, please visit http://hillstead.org