I have several Hulin's Carnival dahlias in my garden, whose flowers are normally white with flecks or large patches of wine:
This year, one of them has put out a stalk that has pink flowers instead of white, keeping the wine flecks:
I would like to preserve this color variation and propagate it if possible. Since it's now fall, I don't think stem cuttings would work (but would be happy to hear differently). These particular dahlias are under an overhang from my porch, so I've been able to leave them in the ground over the winter. If I do that this winter, is a pink flowering stem likely to grow from the same place on the tuber next year? Would digging up the tuber and dividing off the pink-flowering part give me a better chance for success?