Hi Richard, I am in the DFW Texas area and it sounds like we have very similar climate conditions. My tree is new also you can see a picture of it and my garden in the topic "what else do you grow". I am very happy so far with the tree and it's growth. I will tell you what I did: I purchased the tree in mid January from a local nursery - about 4 ft tall 1" or so caliper trunk
March 2 It is in a new garden area - I reclaimed lawn in the back yard which is the North side of the property. For soil prep I (well a friend did this) tilled out the grass and removed it. Tilled the red clay (they try to pass it off as soil here - HA!!!), added a 50/50 mix of bedding soil/top soil, some lava sand (had a bag so what the heck - it can't hurt!) expanded shale - all tilled in. I was trying not to go crazy which was a mistake! I should have gone totally nuts on the soil prep, but I was trying not to overextend the money on this project
The actual planting - I (the friend) dug a hole about 1 1/2 times the depth and about 50% wider. I added more shale, some cotton burr compost and Jobes Organic Fast Start Granular Fertilizer - A couple of handfuls and mixed it in the soil in the hole, loosened the root ball a bit and back filled with the regular soil mix from the prep. The friend who helped was great but I was so anxious to get it in the ground there were things I forgot to do.
About a month later it seemed to not be taking off like I anticipated, so to try and do what I forgot at planting time, I dug around the tree - about 12 inches from the trunk and down about 12 inches and added more cotton burr compost and added more soil up the trunk so it is planted deeper then it was in the pot.
About 2 weeks ago I fertilized with fish emulsion (added to a hose end sprayer - have no idea how much) and sprinkled Epsom Salt to the whole garden.
The tree is planted about 20 ft from the house and gets full sun from 7-8am? (I start work at 1pm, so I usually get up after 8am) until about 3-4pm. As the day goes on, the tree is shaded by my neighbors post oak.
I hope this helps. I understand the emotional attachment you may have with the tree since it was a gift from you son, but you may consider going to the local source and ask if there is a guarantee on the tree.
Good luck and keep us posted
Jo-Ann