Q: I purchased this sugar bush at Desert Survivors Native Plant Nursery two years ago. It chronically looks like it isnโt getting enough water; there are dry, brown leaves. It is planted in desert soil with a cactus mix amendment. It is on a shrub line that runs twice a week right now, for 2ยฝย hours. I have played with the emitter flow and am putting about 20 gallons each application. It gets sun until about 3 p.m. Is there anything I can do to help it thrive?
A:ย Sugar bush (Rhus ovata) is a moderate water user but twice per week at 20 gallons each application seems like a lot of water for a native shrub. If you arenโt checking to see how deep the water is going, I suggest using a soil probe to determine the depth of the watering. Ideally, water should reach a depth of 24 to 36 inches. I recommend backing off your irrigation to once a week for the summer and once every two weeks in the spring and fall.
Overwatering sometimes shows similar symptoms to underwatering, so looks can be deceiving.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed toย tucsongardensage@gmail.com
