Certified GKH Gardening Expert
New tree plantings require daily water for the first 2 weeks, and then you can cut back.
2 to 3 inches of hardwood mulch will help with moisture retention.
Tamp down the soil around the base of the tree to make sure there are not any air pockets around the plant.
If the plant is not growing you may want to have a soil test done.
This will tell you if something is missing from the soil.
Did you plant the tree according to the planting directions on the tag? Most trees or shrubs should be planted at the same level they were in the pot. Planting a tree to deep can cause lack of growth or the death of the tree.
Here are a few links for you.