For our Dahlia fans, there’s still time to dig and save your best-performing varieties from 2023 for next season. Our friends at Arrowhead Dahlias, Harlequin’s supplier of dahlia tubers, have easy instructions for harvesting your tubers.
After the first frost of the season, it is time to dig your dahlias. Dahlia tubers will not survive if they freeze so they must be dug in cold climates, including Colorado. Dividing takes practice and patience, but it is well worth the hassle!
First, dig the entire clump. Your tubers will have multiplied over the season! Gently wash the soil off the clump and divide the tubers by cutting them away from the main clump. Each new tuber must have an eye for growth next spring for flowering, so keep all tubers with eyes, and discard ones without. (They will root, but will not flower). Allow to dry for a short time, bag, and then store them in a cool place that does not freeze. One clump can produce 3-20 new tubers depending on the variety.
The Colorado Dahlia Society suggests adding a cup or two of vermiculite into the bags to prevent them from drying out. Make a few airholes for ventilation in the bags. Check the bags twice during the winter (December and March) and mist the vermiculite with a small amount of water if it has dried out. Keep the bags at a temperature between 35 and 50 degrees. An unheated basement and a garage that stays cool are perfect places to store them.