Saving Dahlia Tubers

• Fall
• Outdoor Plants
• Spring
• Winter

Summer blooming bulbs like dahlia (specifically tubers) and gladiolus (specifically corms) won’t survive in the Berkshire soils through the winter.  You can enjoy them next year again if you spend some time and dig the bulbs up each fall.

Due to the widespread popularity of dahlias, this post will focus on tips for storing and propagating these prolific flowers from year to year.

Storing for Next Season

The goal is to keep them cool and humid but not damp, think root cellar or what the cold produce drawer in your refrigerator does.

Once a hard frost has killed all the green foliage, it’s time to let these bulbs rest.

1. Dig them up and allow soil to dry in a shed or airy porch, out of the sun. You’ll find that compared to planting time, the small clumps of tubers have probably doubled in size!
2. Once soil is dry, gently brush off tubers and put in a cardboard box or other dark but airy container with loose padding of shredded newpaper or similar packing material (wood shavings would be fine). The packing material helps keep them moist but not soggy as the material will absorb and release humidity.
3. If you have different varieties that you wish to keep separate, use separate boxes and write a label for each container or wrap a twist tie with a label around each clump .
4. Keep in a dark, cool location.  Examples would be a crawl space off an unheated cellar or an attached but unheated garage.  Choose a spot that will stay about 40 degrees F through the winter and won’t reach freezing.  If allowed to freeze, the tubers turn to mush.  Don’t keep near heat or in an overly dry location either.

Plan to look in the box in January and again in March to cull any tubers that have grown moldy or too dried out.

Dahlias range in color from deep maroon to sparkly white and many variegations.  If your attempts at storing don’t pan out, you can always stop in for more! We have the tubers available for purchase in early April and potted plants by late May.

Planting in May

Separate large clumps right before replanting in early May. Use a sharp knife to slice apart 2 tubers per plant. The key is to keep a bit of stem attached to the tuber clusters.

Plant in a prepared bed of loose, well drained soil with the old stem just below the soil surface and the cluster of bulbs below. If you know the dahlias get 3 feet tall or more, add stakes around the clump at planting to be ready for tying the dahlia’s stems as the plant grows.

Dahlias make wonderful cut flowers for arrangements.  Once the plants start blooming:

• keep watered regularly,
• feed once a month,
• when cutting for arrangements, cut each flower stem back to a leaf node

You’ll have blooms until frost!