I pruned my Mesquite tree prior in July 4th
Hi, Having to go back North for 8 weeks I pruned my Chilean Mesquite preparing for the Arizona Monsoon season. tree planted 3 yrs ago Trunk now about 5" diam. hight 15 feet x 15' wide Upon my return the tree is 95 % brown ? other 3 trees are fine pruned the same time. Perhaps The heat 110 degrees was to harsh for the late pruning I have a drip ( 3 ) emitters 1 gal hr. every day 15 Min about 1 1/2 quarts a day. all trees the same. When I trimmed I took off branches growing down, and crooked out or rubbing another trying to keep all branches growing up and/or out I did no canopy trimming. I did cut limbs close to the main branches. " Perhaps this was the error"
Certified GKH Gardening Expert
Without seeing the damage, it will be hard to know for certain. It will be most likely that a couple of the trees could have contracted a fungal infection. This is, absolutely, due to timing of pruning.
These trees should really only be pruned during dormancy, but they can take a very, very light pruning in spring.
I would apply a fungicide to the parts of the tree above ground. This article will help: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
You can also treat the ground around the tree with DOLOMITIC LIME and WETTABLE SULFUR according to all packaging instructions.
This article will help you to prune these trees: https://www.gardeningknowhow.com/ornamental/trees/mesquite/mesquite-tree-pruning.htm
This one will help you with general care: https://www.gardeningknowhow.com/ornamental/trees/mesquite/growing-mesquite-trees.htm