Landowners should work with a natural resource professional to develop site-specific tree planting plans. The answer depends on the objectives of the windbreak and the characteristics of the site where the windbreak will be located. The optimum windbreak will include enough trees to provide both wind and snow protection. Figure 1 illustrates a recommended windbreak design. Effectiveness of a windbreak is often expressed in terms of density of the windbreak.
Density is defined as the ratio of the solid area of the trees to the total area of the windbreak.
This can be achieved with multiple rows of dense conifer trees. One or two rows of mixed broadleaf or pine trees can provide this density. Most farmstead or livestock windbreaks should be designed with a density of 40 - 60 percent which can be achieved by planting multiple rows of conifer and broadleaf trees. The most effective protection is obtained by orienting windbreaks perpendicular to the prevailing wind. Windbreaks designed for winter protection are generally located north and west of farmsteads, livestock concentration areas, working facilities or other areas to be protected.