There is considerable controversy over whether or not to stake trees. Certainly, top heavy trees, trees with limited root balls, or trees in heavily exposed or windy areas may need to be staked. However, many trees are staked that do not need to be. The following are some facts about staked versus unstaked trees.
No staking is necessary for newly transplanted trees that can stand by themselves or have branches to the ground. Compared to rigidly staked trees, unstaked trees will: develop a 33% greater basal trunk area; grow 19% less in height; develop a 30% greater trunk taper; develop a stronger, larger root system; develop more uniform xylem to support itself upright; have few or no rubbing or girdling injuries.
Guy wires with rubber hose protectors. Left on more than one growing season. Partial stem girdling. Photo by Andrew Koeser, International Society of Arboriculture, Bugwood.org
Information from the September 3, 2009 edition of the Plant & Pest Advisory, Landscape, Nursery & Turf Edition from Rutgers University http://njaes.rutgers.edu/pubs/plantandpestadvisory/2009/ln090309.pdf