Even though the weather has been unseasonably mild so far this December, winter is in the air and snow is inevitable. Rural landowners can be better prepared to deal with drifting snow if they erect snow fences, says Greg Brenneman, agricultural and biosystems engineering specialist with Iowa State University Extension.
These barriers, either constructed from wood or plastic, prevent snow from blowing across farm fields and blocking streets or driveways. Snow evaporates with the wind so "you don't have to store all the snow in the county, but fences can help you plan for the snow to come," Brenneman adds.
Some snow fences are better than others. "Research shows that the best snow fences are half solid and half open," he says. "Fifty percent porous snow fences let blizzards blow through the slats, but still slow the wind." These fences force drifts to form downwind.
Snow fences must be properly placed to prevent more problems
In the past, wooden picket fences were often used for snow fences. But Brenneman says plastic snow fences are preferred today because they cost less and are lighter weight. However, fencing materials differ in quality and plastic fences designed as safety fences are not as heavy duty as those specifically designed as snow fences.
Snow fences must be properly placed in order to prevent more problems, he points out. If the distance between the fence and road to be protected is less than 30 times the fence height, then the snow drift may reach the road.
"That can make a drift problem worse, instead of eliminating it," he says. For best results, he advises landowners to keep 4-foot snow fences at least 80 feet, and preferably 120 feet, from a road or driveway.
Follow these tips for proper snow fence installation
Brenneman provides the following tips for proper snow fence installation: Locate the fence perpendicular to the prevailing wind direction, make it as long as possible, leave a bottom gap of 6 inches, and ensure that steel posts are on 8-foot centers. Brenneman also recommends that end posts be braced with a steel post driven into the ground at an angle and securely wired to the fence. Plastic fencing materials should be sandwiched between two wood laths and wired tightly to the steel post at the center and near the top and bottom.
Aside from fences, a long-term solution to stop drifting snow is to build up roads and driveways so snow blows across them. "By elevating driveways above the surrounding terrain, wind will sweep snow off the roadway. Usually the roadway must be 1 to 2 feet higher than the nearby landscape to make this effective," he says.
Living snow fences of evergreens and shrubs can be planted as permanent snow fences. A good rule of thumb for living snow fences in Iowa, according to Brenneman, is to allow 100 to 150 feet for trapping snow between the tree planting and the area to be protected. Other techniques to keep roadways clear are to mow down grass and weeds alongside them so snow doesn't accumulate. Also, you should leave cornstalk stubble undisturbed to trap snow in fields.