Great tip, David.
I dug and saved mine for the first time last year. It's easy and it saves time next year. Just one caution; don't do what I did a plant them in good compost without support. They shoot up so fast that a bird landing on them will break off or knock over your plants. I've not had that happen with seed started plants...just the saved tubers.
I had no self-sown sprouts of my hot pink ones from last year, this year, so I was very happy that I saved those tubers.
