If the surface soil of your yard appears dry, that doesn't mean the root zone is in the same arid condition. It can also reveal whether you are watering so much that water is wasted below the root zone. Using this tool can help you judge when to turn off that automatic watering system. Coring tools are available at irrigation supply stores. There is an inexpensive product that may help you establish a new plant or group of plants where an automatic system is not available.
Several manufacturers make a hose from old tires that allows water to seep through the rubber.
The hose can lay on top of the ground or can be slightly buried in the soil or mulch. In our sandy soils, the water will go virtually straight down, so the hose must be placed near the plant's root zones. When the plant is established and no longer needs frequent watering, store the hose for later use. Set several flat-bottom cans or cups at various places within one watering zone. Turn on the sprinklers for 15 minutes.