Trees become established when their roots have developed sufficiently enough to provide for the tree's water and nutrient needs. It should be understood that native trees, once established, should require no futher care other than regular mulching. Trees from areas having summer rains may require supplemental water application throughout their lives.
IRRIGATION- Water applied in the correct amount provides the optimum moisture availability to roots, which increases plant photosynthesis.  Having too much water reduces the amount of airspace in the soil and increases the potential for proliferation of soil pathogens.  Having too little water causes drought stress.  To properly water newly planted trees, information must be available on the soil textural qualities and the amount of water that is being applied.  Until the soil moisture is thoroughly understood, physical soil moisture monitoring is recommended. For a video of what a over irrigated newly planted landscape looks like, Click Here.
MULCHING- Mulching around tree bases provides for moisture retention, reduces soil compaction, controls weeds, and provides a source of nutrition in time.  The recommended mulch is wood chips generated from tree trimmings.  Often, local tree trimming companies will donate mulch.  Good quality (tested) compost is mulch that provides a more immediate source of nutrients and micro-nutrients. 
EARLY STRUCTURAL PRUNING- The most cost effective maintenance a tree can ever receive.  Knowledge of the particular species' branch spacing and location of the first permanent branch are required.  Our City Forest has compiled the teachings of Northern California Urban Forester Bruce Hagen, the National Arbor Day Foundation, and the University Cooperation Extention to prepare a Tree Pruning Guide with excellent Early Structural Pruning Guidelines to help us along in this important process.

Early Care