Before leaving on a 2 week vacation, I put my brand new yellow canna (a Mother's Day gift for a novice)in a pie pan filled with water. Upon return, I found the leaves and flower stalk completed collapsed and mushy. The water was all gone, and the soil was still wet. I dug out the rhizome, and it is soft and sort of mushy. I'm trying to dry it out in partial sun outdoors, but wonder if it stands a chance of regenerating? And what do I do next? Thanks!