It’s all in the design. To get the most benefit from a windbreak and to allow the windbreak to pay for itself, you have to get the design right.
For farmstead windbreaks in the Great Plains, an “L-shape” windbreak pointing in the direction of the predominant winter wind — northwest — is the most popular, says Liz Smith, North Dakota Forest Service forest stewardship manager at Bismarck.
“Livestock windbreaks are often more like field windbreaks — longer lines so the animals can stand in a row or protecting rows of feedlots or barns,” Smith says. “We usually leave the south and east sides of the yard open to allow summer breezes out of the southeast to come in and cool things down.”
Smith says that farmstead and livestock windbreaks need to be dense and located far enough from buildings and access roads, so snow drifts away from those areas instead of right on top of them.
“Often, landowners are reluctant to give up cropland to locate their windbreaks with an optimal setback, or to add additional rows to increase density or add diversity,” Smith explains. “But a properly designed windbreak will pay for itself in improved heating and cooling efficiency; decreased fuel use from moving less snow; increased livestock gains; extended life of machinery, buildings and other infrastructure; and will provide many other benefits that are well worth giving up a couple of acres of cropland.”
What species to plant
“In North Dakota, we are looking at species that have performed well in South Dakota and planting them in trials to see if they perform for us as well,” Smith notes. “A key factor to consider when planning a new windbreak is the other species present either in the existing windbreak or nearby.
“Many planners and landowners get hooked on tried-and-true favorites. However, species diversity offers the windbreak a kind of insurance policy against biotic and abiotic tree killers — because many pests prefer one species over others, and one species may have slightly better tolerance to climate extremes than another.”
Get the right tree in the right place, Smith says, and consider the drier-than-normal conditions many areas have been experiencing lately.
“If possible, use varieties that have been selected and released by a regional USDA-NRCS Plant Materials Center and recommended for your region,” she says. “Be sure the seed source or parent material for the trees comes from the same USDA hardiness zone you are located in.”
Smith recommends seeking the technical assistance of natural resources professionals such as Natural Resources Conservation Service field staff, local soil and water conservation district staff, or Natural Resources District staff and state forest services.
“Start by thoroughly evaluating the site starting below the surface by learning the soil characteristics that may limit windbreak establishment and growth,” Smith says. “Look for slight elevation changes that may cause water to permeate too quickly or too slowly, and modify your planting plan accordingly.”
Once the saplings are planted, they will need to be watered the same day, unless they are being planted into wet soil. One or 2 gallons of water should do it. Pack the furrow or planting hole to ensure good soil-to-root contact, and understand that they may need to be watered during the growing season if it remains too hot and dry.
Weeds and invasive grasses rob trees of moisture. If you can keep grass and weeds at least 6 feet away from young windbreak plantings until the trees or shrubs are 3 to 5 years old, that will increase survivability.
“When properly used, weed barrier fabric does seem to improve windbreak establishment,” Smith says. “But landowners often forget that windbreaks installed with weed barrier still require weeding in the planting hole.”
Fabric barriers also can cause problems as the trees mature, cutting into the bark and eventually girdling the trees.
“Weed barrier doesn’t take the place of hand-weeding and requires annual maintenance, such as opening the planting holes and re-pinning staples in the ground,” Smith adds. There are new tools on the market that provide easier removal of weed barriers after the windbreak has been established.
Learn more by contacting Smith at email@example.com.