Function of a Windbreak on Prairie Land

The Prairies are characterized by high wind exposure, particularly in the Brown and Dark Brown soil zones of southern Alberta and Saskatchewan. Wind is a primary driver of topsoil erosion on bare or lightly residue-covered fields, especially in spring before crop canopy closes. A properly placed windbreak can reduce wind velocity for a distance roughly equal to ten to fifteen times the height of the planting, depending on species density and row configuration.

Shelter belts also modify the microclimate around fields — reducing moisture evaporation from soil, protecting early crop emergence from cold spring winds, and in some cases extending the effective growing window near the planting. These effects are variable and depend on local topography, planting width, and species mix.

Placement and Orientation

Windbreaks are most effective when positioned perpendicular to the dominant wind direction. On most of the Canadian Prairies, the primary erosive winds blow from the northwest or southwest, depending on location and season. Identifying the prevailing wind direction for a specific property — using local weather records or consultation with provincial agencies — is the first step in placement planning.

Field windbreaks are typically placed at intervals across a field. Spacing between parallel windbreaks is often set at a multiple of the expected mature tree height, commonly ten to fifteen times that height. In practice, many existing shelter belts on Prairie farms were planted in the decades following the Dust Bowl of the 1930s, when the Canadian Prairie Farm Rehabilitation Administration (PFRA) distributed seedlings at scale across the region.

The PFRA Shelterbelt Centre in Indian Head, Saskatchewan operated for decades as a key source of adapted tree and shrub seedlings for Prairie landowners. Its programs distributed millions of trees annually. The federal shelterbelt program transitioned in the 2010s, and provincial and private nurseries now supply most restoration plantings.

Species Selection for Western Canada

Not all tree species perform equally across Prairie conditions. Cold tolerance, drought resistance, and soil adaptability vary widely. The following species are commonly referenced in provincial extension resources for Prairie windbreak use:

Conifers

  • White spruce (Picea glauca) — widely adapted across Alberta and Saskatchewan; dense branching provides effective wind screening year-round
  • Scots pine (Pinus sylvestris) — drought-tolerant; performs well in sandy or gravelly soils in drier zones
  • Colorado spruce (Picea pungens) — good wind resistance; used in southern areas with adequate soil moisture

Deciduous Trees

  • Trembling aspen (Populus tremuloides) — fast-growing; spreads by root suckering and provides quick initial coverage
  • Manitoba maple (Acer negundo) — highly tolerant of dry and alkaline soils; often used as an outer row species
  • Green ash (Fraxinus pennsylvanica) — moderately drought-tolerant; affected by emerald ash borer in eastern parts of its range

Shrubs

  • Caragana (Caragana arborescens) — extremely drought and cold tolerant; forms dense low windbreaks and wildlife habitat
  • Sea buckthorn (Hippophae rhamnoides) — nitrogen-fixing; edible berries; used for dense outer rows
  • Saskatoon berry (Amelanchier alnifolia) — native shrub; habitat value; adapted to loam and sandy loam soils

Row Design and Width

Configuration Rows Typical Width Best Use
Single-row shrub 1 2–3 m Light field borders, low wind zones
Two-row mixed 2 5–7 m Moderate wind exposure, crop protection
Multi-row field windbreak 3–5 10–20 m High wind exposure, full field protection
Living snow fence 2–3 5–10 m Road and yard protection, snow management

Establishment and Early Maintenance

Seedlings planted in spring require adequate soil moisture for root establishment. Weed competition in the first one to three years is the primary cause of early failure in windbreak plantings. Mulching, cultivation, or herbicide application along the tree rows is typically required until the canopy closes enough to shade out competing vegetation.

Deer browse is another establishment challenge in many rural areas. Protective tubes or fencing around individual seedlings can reduce browse pressure during the first few growing seasons. Stakes and tree tubes add cost but are frequently recommended in areas with high deer populations.

Long-term Considerations

Established windbreaks require periodic assessment and eventually renovation. Spruce trees on many Prairie farms planted in the 1960s and 1970s are now mature or over-mature, with interior die-back reducing their effectiveness. Replanting with a phased approach — removing alternating trees and establishing new seedlings in the gaps over several years — maintains function while allowing regeneration.

The shading effect of tall conifers can reduce crop yields immediately adjacent to the planting. Some producers accept this trade-off given the broader erosion protection benefit; others maintain a grass buffer strip along the windbreak edge to reduce the competition zone.

Species recommendations and design parameters vary by region and soil type. Provincial forestry and agriculture departments publish windbreak guides tailored to specific soil zones. Consult local extension resources before purchasing seedlings or planning a new planting.

Additional References