1st, I am locked down 200 miles from my garden so cannot provide you with any tubers, sorry as I would have been happy to do so.
2nd, Invasive is a gross under statement. They make mint look weak and lacking in conviction. They seen to spread by both seed and runner. The runners break off and sprout new plants when you weed them. I struggle to keep them out of my raised beds and they are in two foot tall
concrete block structures. I fought nut grass as a kid in central Fla and now am fighting these rattlesnake eggs in N. Fla.
3rd, They grow like crazy and produce well. I weeded a bushel from one 20x4 ft
raised bed last year where they had gotten out of control and have no idea what is going to be awaiting this year. I need a couple good recipes.