Brian Whyer brian.whyer@btinternet.com
Thu, 10 Mar 2011 10:57:23 PST
Dahlia nurseries will grow named forms year after year taking cuttings from their previous years tubers, with the same quality each year. If you are planting or splitting tubers and restrict the shoots to just 2 or 3 then they should be little different from the previous year. If you grow from tubers they will flower slightly earlier than from rooted cuttings, presumably because the plant does not have to form a new tuber system first. Usefull for the large flowered monsters which tend to flower late. Disbudding side shoots will give you larger flowers.
I think named form Dahlias are only cheap in countries where they don't have to be lifted and stored each year, or if you grow seed strains.
Brian Whyer, Buckinghamshire, England, zone ~8

There are no hardy ones that I am aware of. I can winter them over, keep dry in paper bags, but the second year's display is never the same as the first, from freshly bought tubers. For me, anyway. 

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