We bought two American Sweet-gum trees. We live in Pollock Pines, just at the border of Zone 7 in California. The earth is red, between clayish and loamy. The trees we bought (at the Home Depot) were already 12 feet tall in pots. I dug a nice wide pot- deep hole, amended the soil with 1/3 steer-manure, Ammonium Sulfate (for Nitrogen, and an extra 15-15-15 mix high on Phosphorus and Potash). I added some "soil-buster", to help making the dirt more porous. I do this type of amendment on all my new plants and they are all doing well.
The roots were extremely root-bound in those pots, so much that the bottom section was sealed in like coated with a layer of varnish. According to what I read, I made a few vertical slices in the root-ball with a utility knife and tried to get some roots to spread outward. After planting I covered the top with redwood mulch, watered thoroughly every day, but everyday the tree leaves went more limp, so I stopped watering for a day, no improvement. I worry that those trees will die.

Any ideas??

I don't know much about those trees, and planting such large trees in general. We have all kind of other trees planted successfully.

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helmut

Thanks for the advice! What I did now is this in the meantime (that's before I got a response). I did test the soil 10 inches down, it was very soggy. I took the tree out, hosed off the roots really well, and stuck it to the middle of the root ball in clean water, and left it for over night. Tomorrow I will do what you recommended, pad it in peat moss, and water it till it recovers.
I am going to dig a drain channel and fill it with 3/4 " gravel, to drain out the bottom of the hole. The second Sweet gum tree is not doing so badly but not well either. I will do the same with it.

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helmut