Watering is another critical consideration to a productive orchard. While the old fashioned method of using a sprinkler is easy in that you can set it and forget it, it is not the best. Hand watering with a hose insures the plant will get all of the water it needs but can be very time consuming, especially if you have a large orchard.
The best method for watering plants is a drip irrigation method. This is especially handy if you are using rain barrels to gather and store water. Determining how much water a tree needs is not so much a matter of watering time as it is about the depth of moisture. The general rule of thumb is that the top 4 to 5 inches of soil should be moist most of the time. In hot, dry weather with sandy soil this might mean you need to irrigate for an hour every two days. In a rich loam soil with modest precipitation you might only need to water once a week.