Most people supplement summer rainfall with sprinklers or irrigation hoses. Using a lawn or garden sprinkler isn't difficult, provided you follow a few simple rules, states David Robson, horticulture educator with University of Illinois Extension at the Springfield Center.

Most lawns, flowers and vegetables require an inch of water per week throughout their growing season. Shade trees might be able to get by with less, adds Robson. However, bearing fruit trees will need as much.

Sprinklers and irrigation hoses aren't calibrated for home use due to differences in water pressures, soil types and plant requirements. There is no way to state a correct number of hours to water plants properly.

However, homeowners can calibrate their own sprinkler or hose to determine amount of water flow over a specific time. Sprinklers vary considerably. Patterns can be oval, rectangular or circular.

Sprinklers seldom discharge water uniformly. More water is usually released closer to the sprinkler. For that reason, homeowners are encouraged to overlap sprinkler patterns by a fourth.

To determine water flow rate, set the sprinkler in an open area and turn on the water. Place a small tin can, such as a tuna fish or cat food can, approximately three quarters the distance from the sprinkler to the outer edge of water discharge.

Most of these cans are an inch high. When full, check the time. That should give you a rough idea in the future for watering.

Most homeowners will be surprised that it may take more than an hour to supply the recommended inch of water for turf, vegetables and flowers.

To measure irrigation hoses, allow them to soak for a half hour and then test the soil surrounding them. An inch of water will wet the average soil to a depth of 8 to 10 inches. If the soil isn't moist that deep, continue soaking.

A soil probe, steel rod or sharp, straight stick can be used to test the soil's moisture. Wet soil will cling to the probe or rod much like a moist cake.

Homeowners should remember to avoid overwatering plants. Roots need oxygen as much as water and will start rotting if the soil is over saturated.