The tree stake desired and the number required will determine where you purchase your tree stakes. If using a conduit stake in a limited number, you can purchase from a local general hardware or do-it-yourself warehouse. For larger quantities of conduit, you can usually get a volume discount purchasing from an electrical supplier. Also, specialized metal tree stakes can be purchased and shipped as well. A Web search for “orchard tree stakes” will give you several to select from. However, the cost of shipping can be significant and alter the economics of the type of tree stake you use. When using wood support systems, it is best to use turned poles or stakes and not use sawed lumber, due to warping and breakage issues. For limited quantities, these stakes can be purchased at many lumberyards and farm-supply establishments. Larger quantities can be purchased from orchard supply dealers, and they can be shipped to your orchard. In addition, many chemical distributors will also carry this type of material for your inspection and purchase.
Answer provided by Michael Parker, North Carolina State University.