Here are some basic care and maintenance tips on new and existing trees and shrubs:

WATERING
Moisture related problems can cause plants severe stress. Excessive watering or under watering are equally damaging to a plants health. Always consider the type of soils you have before determining a watering schedule. Clay base soils retain water more readily and water leaches faster in sandy base soils. New plants in average well drained soil should be watered at least two times per week for the first year until the ground freezes. A good rule of thumb on existing plants is to consider watering anytime after we have had more than ten to fourteen days without rainfall during hot summer months.

METHODS OF WATERING
A soil probe that can be purchased at most garden centers is the best way to deep root water large trees but can be time consuming and labor intensive on several trees since the probe needs to be moved continually. This method is best because 100% of the water is applied directly to roots beneath the surface and a valve can regulate the quantity applied.
The second best method is with a leaker or canvas hose that applies water slowly unlike a lawn sprinkler that sometimes applies so much water that it runs off before it is absorbed. On large trees the leaker hose should be placed in a circle just inside the drip edge of the tree since this is where conduction occurs at the fibrous roots. For several shrubs the hose can be placed by loosely wrapping it around each plant. One method I like for several shrubs far apart is to buy a cheap plastic or rubber hose and simply poke holes in it at the base of each plant with an ice pick. With this method you don’t waste water between plants.
Do not rely on lawn sprinklers to irrigate plants within a lawn area, the duration of water for grass is not sufficient for trees and shrubs. If you have a lawn irrigation system do consider adding a drip zone on new trees and shrubs with a longer duration.