I'm hardly an expert to answer this; but from what I have found out "size doesn't matter." Each variety produces different size tubers and it has nothing to do with the quality or size of the plant. I ordered from one place this year and got some tubers the size of my fist; and others the size of a pencil. As long as they have an eye; they'll take off. Others...correct me if I'm wrong.

I agree with the above statement.

I have seen no difference in the size of the tubers (between the same varieties) and the size of the plant or quality of it. I have found the 'bulk' tubers that are pretty banged up actually can be seperated 3-6 times. So they send 3 clumps and I end up planting 8-12 seperate plants! They are pretty ratty looking but well worth a little nursing back to health.

Keriann~

Tuber sizes vary so from variety to variety: long and thin, fat like baking potatoes, short round, etc etc. I agree with the above too, and emphasize that any tubers you buy should have eyes if given time for them to pop. If they fail to show up, then it's time to contact the seller. Hopefully, they'll be accommodating.

Last year, as I pulled tomato seedlings sprung from the compost in the garden, I tugged up this little sprout, clearly a dahlia, which had apparently fallen from a parent clump during planting. It went on to grow to full size and even bloom.
{{gwi:639499}}