The pumice says it provides excellent drainage so maybe the Schreiners mix will help prevent rot? That is what I was hoping as well. I had two new ones rotting this spring and it wasn't even a wet one. I have sandy soil which dries out quickly but when it rains here it is usually for a week straight. I don't think the Iris liked that! (It was odd that both the ones that rotted were from the same place, and one was even planted next to the same variety from another vendor and the other is fine. However the same vendor so far has sent me one that wasn't what they were supposed to be. So maybe it wasn't even the same one after all!)
