I agree with all the comments about taking one's time before throwing a tuber out. sometimes they just are slow. I find if I have split the tubers in the fall, and left just a little of the stem with the tuber, then they may take longer than if I leave the whole clump and wait till the lump sprouts. My Wine and roses are like that this year, so I planted them in my raised bed vegi garden until they have a few good leaves --then to be planted in the Dahlia garden. Every week or so i dig them up to check for tuber rot. If there is any, I cut it off, and replant the tuber.
