The amount of water to apply will vary with the plant and the soil type.

Turf needs about 1 to 1 1/2 inches of water per week during the growing season to stay lush and green.

A rule of thumb for watering trees and shrubs is to wet the soil to a depth of 6 to 9 inches.

Annual flowers and vegetables generally need about 1 to 1 1/2 inches of water per week. Water is often most critical for vegetables during pollination and fruit set.

The amount of water being applied by a sprinkler system is easy to determine. Simply place several straight-sided containers or rain gauges around the sprinkler. When the water in the containers reaches the desired depth, stop watering.

Frequency of Watering

The basic idea behind water efficient irrigation is to water lawns and landscape plants only when they need it, rather than according to a set schedule.

• How frequently you need to water depends on soil type, weather conditions, and the type of plant.

• Sandy soils generally require more frequent watering than clay soils.

• Windy, sunny days increase the amount of water lost through evaporation and transpiration, and subsequently the frequency of irrigation.

• Older, more established plants can generally go for longer periods of time between irritations than can newer plants.

There are several methods to determine if a lawn needs water. The easiest way is to test for a loss of resiliency. This is done by walking across the lawn and then checking for footprints. If your footprints remain for more than a few seconds, the lawn needs watering. A dull appearance and folded blades that expose their bases are other visual signs.

Water needs can also be determined by inspecting the soil. These methods may be a little more reliable. One method is to insert a pencil into the soil to a depth of 4 to 6 inches. If the tip comes out damp, you should not water. You can also use soil probes or moisture sensors to check how far the water has penetrated. If the top inch or two of soil beneath a lawn is dry, then you should start watering.

The rate of water application should not exceed the rate at which water can be absorbed by the soil.

Runoff is a serious problem associated with application rates that are too high. Runoff is a big problem on slopes, where it can cause erosion. Water should be applied to the slopes at a slow rate. One possible method is to water for a short period until water begins to run off, and then wait for the water to soak in. Repeat this process until the soil is wet to the desired depth

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