Burlap that is not treated or synthetic is biodegradable. Although a single layer of natural burlap probably wouldn't have much effect on root growth, most experts advise cutting away strings and trimming away the burlap from the upper two-thirds of the root ball. Don't fold the burlap back into the hole because it may interfere with root growth during the crucial time after planting.
Wire baskets should be removed entirely, as long as the root ball holds together. Otherwise, cut some of the wires and leave others in place for structural purposes.
If a shrub or tree has been grown in a container, remove the container completely before planting by working a sharp knife around the edge of the container until the root ball is released.
Delay fertilization for the first year; research has shown that newly transplanted shrubs do not respond to fertilization. If the shrub has become root bound, "tease" out the roots by gently releasing them from the outside of the root ball.