Use Drip Irrigation
One of the best ways to water a garden is with a drip irrigation system. Drip irrigation is the controlled application of water at a very low flow over a prolonged period. It differs from conventional watering systems in that the soil is not supersaturated with water. When the rate of drip irrigation is adjusted correctly, there are no puddles of water and no runoff.
Some drip systems use small water-releasing mechanisms called emitters which drip a certain volume of water when a certain amount of water pressure is supplied. Many of these systems are prepackaged and allow little versatility or adaptation to various garden sizes and shapes.
Several systems currently available in garden centers can be easily adapted to almost any garden size and situation. The most common system has small holes in plastic tubes which allow the water to come out in small amounts. The tube is placed along the row so that the root zone is moistened by the dripping water. Holes are pre-punched in the tubing at 12-inch intervals so that adequate water is available for all vegetable crops.
Once the drip irrigation system is in place and operating, the question always arises as to how long it should be used. A general recommendation is to operate the system three hours a day on alternating days, such as Monday, Wednesday and Friday. When rainfall is adequate, it is not necessary to water for several days. To insure adequate moisture when the garden is planted, apply at least 2 inches of water to the planting zone before seeding or transplanting (pre-irrigation). Be sure the rows are well-firmed at the time of pre-irrigation so the water moves laterally in the soil at well as downward. In many cases, sprinkling the entire garden area may be necessary to settle the soil enough for drip irrigation water to move horizontally and not go straight down in the rows. This is especially necessary in gardens with sandy soil.¶