Most landscapes are over-watered! How do you know how much to water? The simplest way is to purchase a soil moisture meter (about $10 to $15) and poke it in the ground. You will be shocked at how long you can go before you need to water. Plants do not like to be watered every day. Not even high-water-using cool-season turf grass (except in summer). Plant roots need gaseous oxygen in addition to water. The best way to schedule watering for the sake of the plant's health is to allow the water content in the soil to dry down between watering days. For those who like a schedule, the following guide is based on weather data collected at UC Riverside. It assumes no rain, and is based on the water needs of cool-season turfgrass (a high water-using plant species).

If you have looked at the plant lists, you may notice some species that have a higher water requirement than others. They may need more water to get established, but once a plant has been in the ground a year or two, the frequency with which the plant needs water is reduced, particularly if it becomes a woody plant (like a shrub or tree). On the days that a plant is watered, it is important to water the entire root zone and a little bit beyond to encourage deep rooting. A good rule of thumb is to water deeply and infrequently.