We have two chinese pistachios trees in our backyard within 10 feet of each other, one of the trees leaves are turning brown and dying the other tree is healthy. This started last year at the end of the season, we thought maybe we were watering to much, but we only water 3 times a week in the hottest part of the summer for 10 min. We thought this year the tree would be fine, it put out leaves and look fine until it started getting hot. Any ideas what we can do to get it healthy again.
Thanks
Cathy