This is an invitation to play in the mud after some much needed rain! One of the best ways to determine when to water is to take a closer look at what kind of soils you have. Soil is the foundation of the landscape and without a better understanding of the type of soil you have, landscaping can be a costly experiment. The topography or grade above ground is directly related to what is below. For example, low lying coastal areas are predominantly sand as opposed to the Highlands which are predominantly rock. And between those two extremes there is everything in between!
While soil testing is optimal, a quick way to determine how fast water infiltrates your soil is to scratch a few inches below the surface to scoop a handful of earth. If the earth holds its form easily like clay then watering less frequently (not allowing soil to completely dry out) is recommended. If the earth easily crumbles in your hand similar to sand then watering more frequently is recommended. You can also test the soil moisture by seeing how dirty your hands are afterwards. If the earth easily brushes off your hands then it is time to water!