Q.Chinese Pistachio trees
My trees are 3 ft tall and have lost there leaves and branches one has branches at top that have leaves, the other one has lost all its branches except the very bottom ones. I live in central Florida.What is going on.
First, make sure your tree is planted in an appropriate site for the species:
https://www.gardeningknowhow.com/ornamental/trees/chinese-pistache/growing-chinese-pistache-tree.htm
If it's not, it likely will never be healthy. If that's not the issue, it may have a disease or pest problem. Please see the list of diseases on the right side of the follwing webpage. Verticillium wilt especially is a possibility:
http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/chinesepistache.html