Re: dahlia tubers ??
You rang?
Still a bit early to start off dahlias, I normally kick off in March.
With new tubers I feel them over, making sure they feel fleshy and firm. (Behave Mups) Soak in water for a couple of hours if they feel flaccid and dry.
Using a general-purpose compost, part-fill large pots or deep trays. Place each tuber, add labels, cover with compost and water well.
You can take cuttings if you wish as they develop if you want to increase your stock, or just put them into large pots or in the ground and hey bingo, come May June you should see some beautiful flowers starting to develop, a lot depends on weather of course.
My greenhouse grown dahlias don’t go out until May.