I plant mine like Greg plants his -- top of the rhizome just visible with the expectation that the soil will settle and it will end up with just a bit more showing. I also had some of the soft rot issues -- most of it in the new temporary bed which had no leaves for mulch over the winter, but which stays wetter longer than any of the other beds because it's on the north side of the garage -- limited sunlight. And yes -- same discovery with mine -- no warning, but one morning I would find the entire plant keeled over and laying on the ground. I was able to salvage one of those cultivars and I did what Bonnie did -- cut away the bad stuff, dipped in bleach water, and replanted. Last I looked -- it was hanging on.
And -- same thing here -- no odor to the rot, rhizome just turned a dark corky brown.
