I wish they did- but, I'm no expert and I'm fairly sure they do not. However- I have heard some people say you can cut the tubers in half as long as they are coated in sulphur?- (on the cut surfaces) and perhaps with a 'wing and a prayer' or two....you MIGHT get two plants. Personally - I would sooner just buy new ones....eg. 6 tubers for a fiver at Dobbies....

It would be good if they did!!. Like Begoniafan says you can cut the tubers and dust the cut edges with sulphur....BUT, each piece must have a viable shoot.