- Living snow fences can increase driver visibility, reduce road maintenance costs and create wildlife habitat.
- Plants in a living snow fence need to be winter hardy and should be suitable for the climate, site and soils.
- Financial assistance programs are available for interested landowners.
- Shrub willows are efficient and cost effective plants for living snow fences.
Living snow fences (LSF) are plants such as trees, shrubs and native grasses, planted to manage blowing and drifting snow and protect roadways, farmsteads, livestock facilities and communities. These fences form a wind barrier that slows the wind, causing the snow to drop in and downwind of the planting, protecting the road or property downwind.
Living snow fences offer multiple benefits:
- Travel time savings and driver visibility.
- Reduced accidents.
- Reduced annual maintenance.
- Snow and dust containment.
- Wildlife and pollinator food and habitat.
- Managing soil moisture in crop fields.
Blowing and drifting snow on roadways is a major transportation safety and mobility concern. It can cause accidents and require expensive winter roadway maintenance. These issues can be especially problematic near farmlands, where snow can drift onto roadways from harvested fields.
To address these problems, the Minnesota Department of Transportation (MnDOT) operates a program that pays landowners in identified problem areas to plant living snow fences of trees and shrubs to reduce the volume of snow blowing or drifting onto roadways. Standing corn rows can also act as a windbreak.
MnDOT traffic safety data suggest that using LSFs can reduce snow and ice-related accidents. A MnDOT traffic safety study found LSFs that protect curves in roadways can reduce crash severity by 40 percent.
- Select plants that can grow to a mature height of 6 to 12 feet tall.
- Plant multiple rows (typically 2 rows is sufficient) to achieve 25 to 50% vegetation porosity.
- Extend planting length of the LSF 30 degrees further out from both ends of the planting beyond the area to be protected.
- This helps reduce snow drifting problems at the ends of the LSF.
- Use a proper setback distance based on the Snow Control Design Tool.
- A setback range of 75 to 250 feet from the highway right of way is common.
Planting and maintenance
- Proper soil preparation is important if planting by hand or with a tree planter.
- Control competing vegetation in the fall before planting.
- Control weeds the first 3–5 years after planting.
- Consider a fabric weed barrier or mulch for weed control and water conservation.
- Water plants regularly the first 3 years (2–5 gallons per plant every 2–3 weeks if dry).
- Protect plants from deer and rabbit damage by using plant tubes, guards or fencing if needed.
- Monitor the site every other month in the summer for weeds, plant health, insects or disease.
- Check LSF sites after storms for broken limbs and severely damaged trees.
- Prune trees or shrubs for long-term growth, form and health.
- Replace dead plants.
Tree and shrub selection
Proper plant selection for a living snow fence is extremely important to ensure an effective, long-lasting planting. Plants need to be winter hardy and should be suitable for the climate, site and soils. If multiple rows are planted, each row should be a different species.
Many plants can offer potential income or food benefits such as energy biomass, edible berries and nuts, decorative florals and materials, craft and medicinal products, and specialty woods. Consider using native plants when possible.
See Selecting trees and shrubs for windbreaks for more information on suitable trees for your living snow fence.
Planting shrub willows for living snow fences
Shrub willows can provide multiple benefits for humans and the environment. They can be cut and used for bioenergy, decorative florals (pussy willow, etc.) or multiple products.
A UMN research project planted willows in 2013 on the MnDOT right of way bordering the north side of U.S. Hwy. 14 south of Waseca. Read about how the willows were harvested and used to create art at the Minnesota Landscape Arboretum.
- Determine a proper setback distance with the Snow Control Design Tool.
- Snow drifts will collect 10 times the height of the planting on the downwind side. A 10 foot willow could cause drifting downwind up to 100 feet.
- A setback range of 100 to 200 feet from the highway right of way is common.
- Determine the proper width and number of rows to be planted.
- Extending the planting length of the LSF further out on one end may be required to reduce drifting problems around the edges.
- Fast-growing willows can have massive snow catching capacity and reduced drift length shortly after planting.
- Nurseries usually sell willows as bare root stock or sticks for larger plantings.
- Double A Willow in Fredonia, N.Y., is a recommended source of planting stock. They supply cuttings of varieties developed for rapid growth, plant form favorable to LSFs, and pest resistance.
- The sticks they provide are 8 to 12 inches long.
- Plant shrub willows at 2.5 feet between rows and 2 feet apart within the row.
- Barefoot plants and sticks can be planted with a pull-behind tree planter or by hand.
- Soil preparation and weed control is critical to the survival and rapid growth of young willows.
- Perennial weeds or grass may be treated before and after tillage with systemic herbicides.
- Weeds may need to be controlled for the first two years.
- Biodegradable fabric weed mats can slow weed growth around the seedling but needs to be cut in an X pattern (around the willow) so it does not girdle the willows.
- Cutting or coppicing (cutting at the base) on a regular basis (every 2 to 5 years) can revitalize the plants but is not required.
CAUTION: Mention of a herbicide or use of a herbicide label is for educational purposes only. Always follow the herbicide label directions attached to the herbicide container you are using. Remember, the label is the law.
- Willows were coppiced (cut at the base) after the first growing season to generate multiple stems. This is a standard practice for growing willows.
- Willows in the LSF demonstration had average heights of approximately 1 m (3.3 ft) one growing season after coppice. The average optical porosity (the percentage of open space) in willows was 89%.
- 50% porosity is optimal, which could be reached the 2nd year.
- Height and porosity are both important predictors of the snow trapping effectiveness of snow fences.
- All willow varieties and planting arrangements (2 and 4 rows) were observed to be capturing snow after one growing season post-coppice (2014-2015 winter).
- The average amount of snow caught by the willows was around 2.5 metric tons per linear meter of snow fence.
- Four-row arrangements tended to catch about 20% more snow than two-row arrangements during the 2014-2015 winter.
- This was likely due to lower porosity values (i.e., denser shrubs) in the four-row arrangements.
- No significant difference in snow capture was found among the three willow varieties used in the experiment.
- All varieties produced multiple, small-diameter stems and had similar porosity values.
- This suggests that multiple willow varieties/species adapted to similar growing conditions could be used for LSFs.
- Based on climate models, the snow storage capacity of the willow LSFs one growing season post-coppice did not yet exceed the average amount of blowing snow at the study site.
- However, willow growth models predicted that after the following growing season (2nd growing season) they would be able to exceed the average amount of blowing snow.
- Therefore, the willow LSF could potentially trap all of the blowing snow before it reaches the road.
- In the variety experiment, all willow varieties exceeded the growth of the traditional LSF species (American Cranberry, Gray Dogwood).
- One native willow, Salix petiolaris, had similar growth to the top performing bioenergy willows, “Fish Creek” and “Oneonta.”
- This suggests that native willow shrubs may be just as suitable as bioenergy willows for LSFs.
Cost sharing and annual land rental payments for planting and maintaining living snow fences are available.
The USDA Conservation Reserve Program (CRP) offers cost-share, annual and incentive payments. The Environmental Quality Incentives Program (EQIP) may also offer LSF funds. Contact your county Farm Service Agency (FSA) office for more details.
If the living snow fence will be protecting a designated MnDOT snow problem highway, state MnDOT funds may be available in addition to CRP and EQIP payments. There are also MnDOT funds available for leaving standing corn rows next to designated highways. View the MnDOT website or contact your district office for more information.
Cities and counties may also have LSF programs. Contact your County Highway engineer for details.
Reviewed in 2019