You're bidding on ONE tuber of the the flowers shown, but I'm unable to say which as the tubers are mixed. Sorry folks!

There's no flower yet, just a tuber

Pick up in Hoon Hay

Wikipedia: "...to date [true blue dahlias have] not been accomplished." (how wonderful it'd be!).

"While dahlias produce anthocyanin, an element necessary for the production of the blue, to achieve a true blue color in a plant, the anthocyanin delphinidin needs six hydroxyl groups. To date dahlias have only developed five, so the closest that breeders have come to achieving a "blue" specimen are variations of mauve, purples and lilac hues."

"Dahlias... tuberous nature enables them to survive periods of dormancy, and this characteristic means that gardeners in temperate climates with frosts can grow dahlias successfully, provided the tubers are lifted from the ground and stored in cool yet frost-free conditions during the winter." MINE STAY IN THE GROUND. "Planting the tubers quite deep (10 – 15 cm) also provides some protection. When in active growth, dahlia hybrids perform most successfully in well-watered yet free-draining soils, in situations receiving plenty of sunlight. Taller cultivars usually require some form of staking as they grow, and all garden dahlias need deadheading regularly, once flowering commences."

"Today the dahlia is still considered one of the native ingredients in Oaxacan cuisine; several cultivars are still grown especially for their large, sweet potato-like tubers. Dacopa, an intense mocha-tasting extract from the roasted tubers, is used to flavor beverages throughout Central America."

"In Europe and America, prior to the discovery of insulin in 1923, diabetics—as well as consumptives—were often given a substance called Atlantic starch or diabetic sugar, derived from inulin, a naturally occurring form of fruit sugar, extracted from dahlia tubers. Inulin is still used in clinical tests for kidney functionality."