On 10 Mar 2011, at 13:21, santoury@aol.com wrote: > 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. The dahlia fanciers never use the tubers directly to grow their prize-winning blooms. Instead they bring the over-wintered, dormant tubers into "gentle warmth", merely sitting on damp peat moss (I believe), and let them sprout, then take cuttings. By leaving at least one leaf node below each cutting, you take the dormant buds there begin to grow, so you get a geometrically increasing number of cuttings out of one sprout until the tuber is exhausted. A collateral advantage to growing from cuttings is that if the tuber is infested with some soil borne pathogen, the cutting grown plants will generally be free of it. Dahlias are very interesting as a plant increased strictly by vegetative means (under normal circumstances), yet at least some cultivars don't seem to lose vigor due to increasing virus titer. 'Bishop of Llandaff' is a good century old and still going strong. -- Rodger Whitlock Victoria, British Columbia, Canada