With summer bearing down full force, any problems that have developed with irrigation systems will be easy to spot but possibly tough to recognize. When a single plant wilts or dies, it’s easy to blame insects or disease. But many times it’s a malfunctioning drip irrigation system or poor watering practices that may be the cause. The way to be sure is to get down on your hands and knees and check the soil. If it’s bone dry or swampy wet, turn your system on to make sure the emitters are operating properly. Replace or clean clogged drippers, or repair breaks and leaks (be sure to understand and follow any local water ordinances). Check the lines for kinks, holes or other damage that would prevent water from getting to the plants.
Next, make sure you are watering properly. Most drip emitters are rated by the number of gallons they apply per hour (gph). Half-gallon-per-hour or full-gallon-per-hour emitters are common. To wet the soil to a depth of 18 to 24 inches (the amount needed for many small shrubs), most emitters must run for several hours. Check your system by running it for the usual time. Then probe the soil with a stiff rod or screwdriver. It should move easily through wet soil and stop when it reaches dry soil. Adjust the timer so you wet the soil to the proper depth, and allow several days between irrigations so the soil can partially dry.