Did you put them in gopher cages? We planted a bunch of special apple trees for hard cider a while back and didn't know about the gopher cages. Gophers killed all but one of them. I was watering one tree and the ground opened up and all the water drained down. Grabbed the tree and it came out of the ground in my hand. All the roots had been eaten.
I wish I had the iron in the soil that you probably have with the red color in the photo. Typically, it is the lack of available iron in the soil that can be an issue for the stone fruit. Chances are that you have plenty of available iron and your trees will be happy with that. A&M has lots of great info about fruit trees here in Texas. Womack Nursery is what I use for my trees. They are an excellent family-owned nursery.
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Enjoy the trees!