Any tuber you purchase is technically a 'first year tuber,' a product of the prior season's plant.

The 'mother tuber' (last year's starter tuber) is rarely kept, as most the energy is sapped out of it, and often rot in storage.

Perhaps you feel that the mother tuber needs to be 'acclimated' to your soil or zone before producing tubers that will perform well?

I have grown many, many tubers sent from all over the lower 48, and have not experienced any adjustment period needed. Growers that receive tubers from a different growing cycle like Australia to the US often talk about a lag in performance, but I haven't heard of it otherwise in dahlia grower circles.

If you're not talking about the theory of soil acclimation, please explain to me, because I'm missing something in your logic. :-)

The only logic thing could be that a badly stored, half shriveled tuber (from a big store) would probably need a little bit longer than a healthy well-kept one of the same cultivars.

And about different climates:
If a Dahlia cultivar is bred in a much warmer climate and is adapted to it, then it is fixed in its genom.

And then it could be that it ALWAYS perfoms poorly in colder regions: flowers very late or hardly at all.

That seems to be the case with some Hemerocallis cultivars from the US which don't do well in cooler parts of Europe. But that is permanent.

Very interesting point, so let's hear about it,

Bye, Lin