Yes, the clumps do increase in size. I'm not sure if the term is rhizome or not, but they will get bigger. I suppose if you really were familiar with these, you could even divide large clumps. I sure wouldn't do it though.


A few miles from my house, there is a wildflower garden maintained by the city park department. It's the oldest one (or one of the oldest) of its kind in the country. Anyway, there's a huge clump of the Showy Pink Ladyslipper there. That clump is easily 3 feet across with dozens of individual stems.