You do not need to be an experienced horticulturist to understand proper watering techniques and to enjoy success with your new plants.  The most common cause for failure when new plants are establishing themselves is improper watering, i.e. too much or too little.  There must be sufficient water to get all the way down to the bottom of the root ball and then dry out between waterings.  Do not water by schedule!  Water by current conditions and needs of the plant - deep watering less frequently!  Check conditions by pushing aside mulch and touching the soil and only water if dry.   If you are uncertain about soil conditions, a moisture meter is a simple, useful tool.  The following are some basic rules of a green thumb:

Deep Watering Less Frequently - Shrubs and trees cannot effectively be watered by hand watering.  You must place a hose at the base of the plant and let the water flow for 20 minutes on small shrubs and 2 hours on trees.  If you set up sprinklers on your shrubs, figure on 2-3 hours minimum of watering.  For large plants and trees use your sprinkler overnight. 

Do Not Water By Schedule - Several factors will determine how often your plants need watering.  Among them are soil type, exposure, type and size of plant and recent rainfall. 

Checking Soil Conditions - Pull away the mulch surrounding your plant, shrub or tree.  Dig down 3-4 inches around the edge of the root ball and take up some soil in your hand.  If moisture can be squeezed out, or if it easily sticks together in a ball, do not water.  Check the soil again in a few days.  If, when you take up the soil in your hand, it crumbles and will not stick together, it is time to water. 

Consider Other Factors - Not all areas of your landscape will need to be watered at the same time.  To insure proper watering, check the status of your soil in diverse areas of your landscape, e.g. a sloped area, a flat area, shaded or partially shaded areas, etc.