What kind of tree is this and what is cause it to turn brown and lose leaves. Houston, Texas, Sept 16th. I added more soil and rocks around base to cover the roots better.
Appreciate any help!
Not sure what kind of tree it is (this is a British site) but you may may have provided at least part of the answer yourself. If the tree is not an evergreen then browning and loss of leaves is perfectly normal - it is autumn.
Trees do not respond well to the soil level being raised. Their roots are at or near the surface because that is where they want them to be, so if yiou added more than a very thin layer of soil it may suffer.