I don't know if this make a difference or not, but I too had one die on me, and all the others did really good. The one that died was by itself, and all the others that lived were surrounded by a garden. So I'm wondering if the one that had died was lonely for other plant life. I kept all the cowplants fed according to their needs, including the one that had died. So I'm wondering if having other garden plants around makes a difference on the survival of a cowplant (meaning are they social creatures). I hope that made sense.