However, trees should be hand watered, or watered by a bubbler system frequently after planting, applying water directly on the root ball. A donut of soil built up just inside the outer edge of the root ball can facilitate this practice. Don't over manage your tree plantings. If the new growth remains healthy, you are on your way to success. Sometimes we can be our own worst enemy in this regard.
Most trees can do just fine with relatively minimal management by man.
When we manipulate the tree's environment in unnatural ways, we can cause serious health problems for the tree. Go to the Environmental Horticulture program page for further information.