Windbreaks on the upwind side of a target can be used to reduce the force of the prevailing wind for a distance equal to ten times the height of the windbreak. Wind velocities can actually be increased by funneling air through small openings or forcing it beneath an established tree line. Funneling can be accomplished by creating vertical openings either by removing vegetation or by leaving gaps in plantings. Forcing air down can be accomplished by pruning lower limbs up to 15 or 20 feet and removing undergrowth.

Mixing air can be accomplished by establishing a windbreak downwind of an odor source. Air flows by the source and lifts over the windbreak. This lifting forces the mixing of ground air with air over the windbreak. In the case of some pines this could be over 50 feet high.

Windbreaks should face the prevailing southwest winds in North Carolina. Local winds or other local conditions could dictate otherwise. If air mixing is desired during a wind out of the east, then the windbreak should face east and be west of the target.

Three row plantings are the most effective. The first row (facing the wind) should be dense evergreen shrub, the second row a tall evergreen tree, and the third row a medium height tree. Recommended shrub choices include wax myrtle, Chinese holly, Chinese photenia, or California privet, planted 6 feet apart. Tall evergreen second row tree choices include loblolly pine and longleaf pine, planted eight feet apart. Medium height evergreen tree choices would include Southern magnolia, red cedar, Virginia pine, and Leland cypress, planted eight feet apart. Rows should be ten feet apart with trees and shrubs staggered with rows.

Revised 2/16/2006.