Most soils are crumbly at this stage but not dusty. It is not cool to the touch, and it may be dusty. It is important to water these plants as soon as the soil reaches this state. Although they can usually withstand long periods of drought, they grow much better if watered regularly. How Much Water to Apply Each time you water, apply enough water to wet the soil to the bottom of the root zone.
Water is measured in inches.
If a tin can is placed on a lawn when the sprinklers are turned on, the soil has received an inch of water when the water in the container is an inch deep. Because sandy soils do not hold as much water as clay soils, it takes less water to wet them to the same depth. Soils vary greatly in their ability to hold water, so these figures are only guidelines. To see how much water your soil needs to wet it a foot deep, measure the amount of water you apply at an irrigation. The next day, after the wetting front has moved down as far as it will go, dig a hole to see where the wetting front is.