The purpose of watering is to recharge the soil with water so that reserves will be sufficient to last until the next watering or rainfall. Make sure you always water thoroughly so that water is available deep in the soil. Frequently applying a little water is of limited value because most of it evaporates off the soil surface before it has a chance to penetrate down to the roots of plants. Also do not water plants at a rate that causes puddling on the soil surface. This will lead to run-off and erode the soil.
The water supply is limited to a plant by the size of its root system. Offering your plants a well drained soil without any hard compaction, you will allow them to develop deeper roots and this way you will obtain a comparative increase growth. The rate at which the soil takes up moisture is different from soil to soil. On average soil absorbs about 8 mm depth of water per hour. If the water is applied to the soil faster than it is absorbed than it will form a pool on the surface until it will all be absorbed into the soil.
After watering in dry conditions you should test the soil and see how much water was absorbed. If the soil around the plants roots is still dry than you should apply several further waterings once the water from the first application has soaked in. To reduce the run-off you may modify the ground by terracing or dishing to create a hollow trough around each plant. This will ensure that the water reaches the plant roots. Pot watering, sprinkles and trickle or drip feed systems are efficient methods of watering. By these methods the water is supplied to the roots over several hours.
To conserve water and reduce the amount of watering you must apply mulch to the surface of the soil. This will improve rain penetration and minimize evaporation. Controlling weeds effectively you will ensure that no water is wasted on unwanted plants.