Q: I’m pretty sure my palo verde tree is suffering from major beetle damage. Many branches are dead, it barely leafed out, and there are many holes in the ground that are very deep. I will take advantage of the holes and do deep watering, but what else can I do to save it?
A: I think you need to have your tree pruned to remove the dead and damaged branches. I recommend using an ISA-certified arborist so the quality of the work is more or less guaranteed. The International Society of Arboriculture has a web site (www.isa-arbor.com) that allows you to search for arborists in your area. The palo verde beetles you collected are very commonly seen during the monsoon season and not a big concern. If the tree is healthy, it should be able to withstand a few beetles. They likely made the holes you are using. Good irrigation is critical to maintaining the health of your tree and watering is best done with a drip irrigation system on a timer so you can accomplish it on a schedule and more efficiently. Desert trees like this need a good soak once every two to three weeks in the summer down to about 24 to 36 inches. It’s important to put your irrigation emitters around the root zone near the outside of the crown of the tree so it reaches the absorbing roots.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed to plwarren@cals.arizona.edu
