When a spruce tree is transplanted, its roots go into shock, which limits their ability to absorb water. They'll need extra water in order to recover from transplant shock. However, applying too much water is just as bad as not watering at all. Overwatering can kill the tree, so checking the soil moisture before watering is critical.
Press down on the soil 12 inches away from the base of the tree with your foot. Look at where your shoe meets the soil to see if water appears or if there is an audible squishing sound. This indicates the spruce is overwatered.
Look at the lowest limbs of the spruce tree to see if they are brown or yellow in color. Overwatered spruce trees begin to die from the bottom up.
Crouch down and look at the soil under the tree to see if mushrooms or a white mold-like growth is present. These only grow in constantly soggy soil and indicate the soil is overwatered.
Make a note on a calendar every day that rainfall occurs as well as ever day that you water the spruce tree. Spruce trees only require one day of water per week, which amounts to about 1 inch per week.