While you can obviously water your vegetable garden with an oscillating or impulse sprinkler, the better choice is the porous hose (also called “soaker” hose) for the vegetable garden. It dribbles water out of the length of the hose through millions of little pores and all the water goes into the ground.
There are watering systems that release water very slowly at soil level and do not allow any water to get on the leaves of the plants. These drip or soaker irrigation systems, as they are called, offer a number of important benefits to the yard and garden. They are not appropriate for watering lawns, but they are preferred methods for watering vegetable gardens, flower beds, trees and shrubs.
A typical porous hose will water your veggies out to a foot on each side of the hose (in sandy soil the spread is only about 8 inches on each side).
First and foremost, these systems use much less water than the overhead sprinkler. You can assume that you will save at least 30 percent, and in some cases 50 percent, of your water over sprinklers or other methods of watering. Water delivered by a drip or soaker system has no chance to evaporate or run off, because it is completely absorbed by the soil and never touches the leaves of the plants.
Research has demonstrated that drip or soaker irrigation systems, especially those used in conjunction with mulch, increase the plant’s performance. Plants show earlier blossoming, increased growth, and larger blooms. Because the water never touches plant leaves, they avoid many moisture-related diseases.
Problems such as rust, mildew, and blossom damage are all reduced in gardens using a drip technique. Another advantage is the cooling effect a drip or soaker system has on the soil. A properly managed drip or soaker irrigation system can be used to help keep down soil temperatures in the high heat of summer. This increases production, because plants grow more effectively in the cooler soil.
Finally, a drip or soaker irrigation system reduces the problem of soil compaction. When the soil is saturated with large amounts of water, its structure breaks down and compaction occurs. Drip or soaker irrigation reduces this problem because the water is introduced into the soil so slowly that the structure of the soil is not affected.
With no adjustments needed for evaporation and run off, you can plan your watering task around the need to get about one inch of water to your plants each week from rain or from your drip system. That is about two quarts of water per square foot of garden per week. All you have to do is find out how much water your particular drip or soaker system releases over time, and you can then calculate how long each day or every two or three days you need to run your system. The trick is to set an empty tuna fish or cat food can under the drip emitter or the soaker hose. Time how long it takes to fill the can and you have the time it takes to get an inch of water approximately.