Trees and shrubs should be planted with all metal, plastic or fiber containers, netting, wire mesh, burlap, twine or any other obstruction to the roots or trunk removed. Place the plant in the hole so that the top of the root ball is at or just above ground level. With a utility knife, lightly score the root ball on four sides approximately one-quarter of an inch deep without disturbing the main root ball. Loosen and straighten larger encircling roots.
Fill the hole with loose dirt, but don’t pack the soil. When the hole is three-fourths full of soil, slowly add water and finish filling the hole. Make sure the top of the soil slopes away from the trunk of the tree. Erect a dam around the outside of the hole with soil. Fill the depression inside the dam with water and allow it to seep in thoroughly. Check for any areas that have caved in around the plant and fill those holes with soil. Again, do not pack the soil, especially after it is wet. Add two to three inches of mulch over the ball, but not all of the way to the trunk.
Small trees do not need staking, but stake tall and large trees, especially evergreens. Place stakes parallel to prevailing winds. Use only tree straps around the tree trunk. Wire through the strap’s eyelets and attach to the stake. The top of the straps should be at the first major branch or trunk crotch, or at about two-thirds the height of the tree. Remove the stakes after the first year.
For more information, see the following Colorado State University Extension fact sheet(s).