Watering in small amounts every night might keep your grass looking green, but it will not get water to your trees and shrubs because you are only getting the first couple inches of soil wet. The grass will use all the water and none of it will get down to the deeper roots of most trees and shrubs. I recommend that you start watering for longer periods less often. This will not only help your trees, but it will also help make your grass develop a deeper root system and be more drought resistant. For more information on watering new or existing trees, visit the eXtension site: Trees and Shrubs" Maintenance.
