"How often should I water my trees?" is a frequently asked question here at Osuna Nursery. Our Landscape Architect, Louise Janney, offers suggestions below.
Here is our standard recommendation on tree watering, but there are many variables: You will first need to find out how much water is coming out of the drip emitter and ensure you meet the requirements. When weather is hot, trees lose more water to dry air, so you'll need to water more. In winter, you still need to water plants as we don't get that much snow... run the drip system at least once a month.
A general rule of thumb is to apply 10 gallons of water for every inch of trunk diameter weekly, unless the trees are Desert Willow or New Mexico Olive drought-tolerant species. Measure the trunk diameter at knee height. You can eyeball the diameter or hold up a ruler or yardstick to get the inches. The general watering formula is: tree diameter x five minutes = total watering time. 90% of the roots are in the top 12 inches of soil, and many of the roots that take up water are located in the dripline area. If water is placed below 12 inches, the tree misses out.