The 6 Main Shelterbelt Species

Common Caragana (Caragana arborescens)

  • Common caragana, or Siberian peashrub, is a species of legume introduced into Canada from Siberia. Characteristics of this broadleaf shrub include: 
    • Grows up to 5 meters tall;
    • Pinnately compound leaves up to 8 cm long; 4-6 pairs of leaflets;
    • Small, yellow flowers which can grow alone or in clusters that ultimately turn into pods;
  • Lifespan/rate of growth:
    • Moderate-fast growing and lives 50+ years.  
  • Environment:
    • Adapted to and suitable for sandy to loamy soils (prefers well-drained).
    • Extremely drought-tolerant and can grow in low-nutrient environments.
    • Adapted to cold climates seeing as it is native to Siberia.
    • Prefers full sun conditions and should remain in the outside of the shelterbelt.
    • Should not be planted in areas of repeated flooding as it grows best on well-drained sites.
  • Useful for: 
    • Attracting wildlife and pollinators as well as for aesthetic purposes due to its bright yellow and fragrant flowers.
    • Controlling soil erosion. Caragana has been seen to have an extensive root network and therefore is very beneficial to control erosion.
    • Trapping snow.
    • Proficiently fixing atmospheric nitrogen.
Image 1. A row of common caragana.
Source: https://www.minnesotawildflowers.info/udata/r9ndp23q/pd3/caragana-arborescens_012.jpg
Image 2. The pods of common caragana.
Source: https://lh3.googleusercontent.com/proxy/vdBZ_4AzvtQ5IyXBssHdFB2WBVT0UWeW5IXCOAGpGfdWXnqprItstLUxHyottb6DHxm4pkNyTBw1dv0cbnzLbK4zS4B06tQTuRQwWoP6Sq6_dTg_nZzAx7Ncdt-FGGNjeZQMclgoGA

Scots pine (Pinus sylvestris)

  • Scots pine is an evergreen tree species introduced to Canada from Europe and Asia. 
    • Grows up to 18 meters high 
    • 2-sided blue-green needles, slightly twisted and grown in pairs, 2.5-5 cm in length  
    • Grey-brown bark, transitioning to orange as height increases
    • Cones 3-7.5 cm in length 
    • Often irregularly shaped 
  • Lifespan/rate of growth: 
    • Grows at a slow-moderate rate, living up to 300+ years. 
  • Environment:
    • Can successfully grow in many environments. However, it grows best in well-drained or sandy soils, and requires full sun and cannot tolerate shade or flooding.
  • Useful for:
    • Scots pine is useful within shelterbelts because it can successfully grow in many soil and moisture conditions.
    • A source of food and habitat for wildlife.
    • A source of wind and snow cover for farm animals.
    • Controlling soil erosion.
    • Thermal cover.
Image 3. A mature Scots pine shelterbelt.
Source: Colin Laroque

Green ash (Fraxinus pennsylvanica)

  • Green ash is a hardy species of deciduous tree native to Canada and the northern continental United States. Characteristics of this species include:
    • Grows 15-20 meters high 
    • Opposite leaves with 7-9 leaflets 5-12 cm long 
    • Smooth, grey bark, thickening with age 
  • Lifespan/rate of growth: 
    • Moderate-fast growth rate and lives 50+ years.
  • Environment:
    • Although green ash grows best on moist and fertile soils, it is adaptable to many soil types.
    • Green ash prefers full sun and is drought tolerant, as is Caragana. 
  • Useful for:
    • Green ash is useful in shelterbelts because it is adaptable to many soil types.
    • Quite noncompetitive and grows especially well with Caragana, so it is often beneficial to plant these two species together, as this increases green ash height as well as shelterbelt snow trapping capabilities.
    • A source of food and habitat for wildlife and blocking wind.
Image 4. A mature green ash field shelterbelt beside a field of canola.
Source: Colin Laroque

Hybrid poplar (combined Populus spp. such as Populus canadensis)

  • A hybrid poplar plant is a deciduous tree of which various poplar species are artificially or naturally combined. An example is Canadian poplar or Carolina poplar, Populus canadensis, which is a natural hybrid of black poplar (Populus nigra) and Eastern cottonwood (Populus deltoides). 
  • Poplar and cottonwood species in the Populus genus are part of the Willow (Salicaceae) family. Common characteristics of tree species in this family include: 
    • Normally have alternating, rounded-triangular leaves 7-15 cm in length.
    • Grows to a height of 25 meters.
    • Drooping wooly catkins appearing before leaves, containing flowers or numerous small seeds in capsules.
    • Bark is furrowed to smooth.
  • Environment:
    • Prefer full sun.
    • Grow best in wet, acidic and alkaline soils. 
  • Lifespan/rate of growth:
    • Very fast growing but short-lived species, living 30-50 years. 
  • Useful for:
    • Blocking wind as they increase their height very rapidly. 
    • Reducing wind erosion and trapping snow.
    • Reducing stress of livestock.
    • A source of food and habitat for wildlife.
    • Controlling farm/environmental odours.
    • Filtering water.
Image 5. Wooly catkins and leaves of hybrid poplar.
Source: https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Salicaceae/populus-deltoides-fr-atal.jpg
Image 6. A mature hybrid poplar shelterbelt.
Source: Colin Laroque

Manitoba maple (Acer negundo)

  • The Manitoba maple, or Boxelder Maple, is a deciduous maple tree native to Canada. Characteristics include:
    • Grows up to 15 meters tall, and is the largest Prairie-native maple species 
    • Unique leaves with 3-9 opposite leaflets, each 5-25 cm long
    • Fruit a schizocarp of 2 attached samaras containing 1 seed each  
    • Flowers 4-20 per cluster
    • Brown-dark grey rough bark
  • Lifespan/rate of growth:
    • A moderate-fast growing but short-lived tree, living 50+ years.
  • Environment:
    • Easily adaptable to many soil types and moisture levels, from seasonally flooded to dry soils. However, they grow best in full sun and moist soil.
  • Useful for:
    • Manitoba maple is useful in shelterbelts since it is easily adaptable to many soil types and moisture levels.
    • Especially useful for buffering around streambanks and floodplains as this is the environment of which it prefers (e.g., within riparian buffers).
    • Wind protection.
    • A source of food and habitat for wildlife.
    • Pollination as the flowers are a good source of pollen and nectar.
    • A source of syrup.
Image 7. A row of Manitoba maple.
Source: https://i.pinimg.com/originals/47/eb/4c/47eb4c42b2d357708c7d24e0e94402c5.jpg
Image 8. Manitoba maple samaras.
Source: https://blog.growingwithscience.com/wp-content/uploads/2012/12/mystery-seeds-dec1-2.jpg

White Spruce (Picea glauca)

  • Picea glauca is a native, widespread, pyramidal evergreen tree species. Characteristics of this species includes:
    • Regularly grows 20-30 meters high 
    • Spreading, 4-sided, sharply pointed needles up to 1.5 cm in length; needles blue-green and lined white on all 4 sides
    • Brownish, scaled cones, 2 seeds per scale with broad, thin wings
    • Roughened branches from peg-like protrusions of past needles
    • Grey-brown to somewhat reddish bark
  • Lifespan/rate of growth:
    • Slow-moderate growth rate, living anywhere between 250-350 years.
  • Environment:
    • Prefers full sun but tolerates shade, most soil conditions and some drought. It is recommended for the Black soil zone as this area is not consistent with drought.
  • Useful for:
    • A source of food and habitat for wildlife.
    • Source of wind and snow cover for farm animals.
    • Thermal cover.
    • Wind control and trapping snow.
Image 9. A mature white spruce shelterbelt.
Source: Colin Laroque

References