I grew alot of apple trees in N. Mi. I have tried to grow apple trees in SE Iowa. I have found it more difficult in S Iowa. I know the far south does not grow good apples. Did not think S Iowa was that far south. I have a feeling Iowa , with it's long humid summers, not so liked by apples. Along with the disease problems, from Cedar trees, and wet scab. I have disease resistant varieties too. I had some trees die from too wet conditions. I have clay. Had clay in Mi too, but never had a full grown tree die,,as in Iowa. Am tending more to hardy crab apple trees and looking into the Red Fern guy, as he grows trees in Iowa to start with. I say for sure,,stay away from bigger trees found in pots at places like MenaRDS and Lowes. Too large,usually die..