Planning, Planting and Maintenance

Planning your shelterbelt

Overview

Often the most important step in shelterbelt planning is choosing plants that are suitable to successfully grow in your geographic location. Other planning aspects include choosing your shelterbelt design and determining equipment needed. Identifying your concerns of the area and determining how a shelterbelt could help mitigate these concerns is important as well. You should also assess your environment in the area and be sure that it can withstand the addition of a shelterbelt. After planting, monitoring is important to make sure your shelterbelt is making progress at executing your goals. After this, modifications can also be made in areas that you deem necessary.

Image 1. Measurements being taken to determine shelterbelt spacing.
Source: Colin Laroque

Planning

Whatever plans are made for your shelterbelt, one or two alternative designs should also be brainstormed in case the primary design is no longer an option. After the implementation process begins, one might also find that a secondary shelterbelt design may actually be more suitable for your goals. 

Perhaps the most important step in shelterbelt planning is doing research and choosing plants that are suitable to successfully grow in your geographic location. 

Another part of planning your shelterbelt is which shelterbelt design you will select, and the equipment needed to prepare and create such a design.

  • As you plan your shelterbelt, keep the following considerations in mind:
    • Locate your shelterbelt where it will be most effective at its purpose
    • Design the shelterbelt to meet your goals with the available space
    • Choose suitable plants (as mentioned above)
    • Prepare the site before planting any shelterbelt species 
    • Arrange means for labour
    • Provide a nursery or simply care and protection for the seedlings until time for planting
    • Means to control weeds before and after the planting stage 

The objective(s) of your shelterbelt

  • During the planning stage, the potential site for a shelterbelt should be assessed. Identifying your concerns of the area and determining how a shelterbelt could help mitigate these concerns is important. You should also assess your environment in the area and be sure that it can withstand the addition of a shelterbelt. For example, soils low in nutrients might not be able to cope with additions of large plants such as trees. These issues should be taken into consideration before a shelterbelt is implemented. 
  • Potential objectives of a shelterbelt include: 
    • Reduction of: soil erosion, wind disturbance, snow drift and buildup, odour, noise to and from surrounding areas, net greenhouse gas emissions and dust volume
    • Insulation of buildings and reducing energy consumption and costs
    • Protecting, shading and insulating livestock from weather
    • Aesthetics and beautification of the area
    • Providing wildlife habitat and increasing biodiversity of the area 
    • Visual screening
    • Capturing atmospheric carbon
    • Increasing property value

Implementation and monitoring

  • Smaller shelterbelt projects may not require much planning, but larger ones do. 
  • One must consider what means they have available to implement and monitor the potential shelterbelt. Are the proper supplies and resources available, such as laborers, tools, machinery, and solutions (e.g., herbicides)?
  • After planting, monitoring is important to make sure your shelterbelt is making progress at executing your goals. It may take years for you to conclude whether it has or not. This is why it is important to regularly monitor your shelterbelt. 

Modifications

  • After implementing and monitoring your shelterbelt for a period of time, modifications can be made in areas that you deem necessary. Areas such as weed management or pruning methods can be altered. A trial-and-error basis may be necessary, but be sure to do research before altering your environment again in new ways, to prevent unnecessary damage. 
  • Objectives also can be modified or additional ones can arise. Priorities may have changed altogether. With proper planning of new objectives and modifications, there is a better chance that all (new or old) goals can be met. 

Shelterbelt Design

Overview

There are several types of trees and shrubs that can be used in a shelterbelt for various purposes. Different plant species have different growth times, heights, densities, lifespans, etc., which all play a role in creating shelterbelts with various purposes. Creating a sketch of the shelterbelt area can greatly help the planning and designing process. 

Different plant species have different growth times as well as characteristics such as height, density and longevity which all play a role in creating a successful shelterbelt. 

  • Height
    • Shelterbelt height of course influences the area that the shelterbelt will affect. With a taller shelterbelt, more area is protected. 
  • Growth times and longevity
    • If you want your shelterbelt to come into effect quickly, decide on fast-growing tree and shrub species. Fast-growing species are often also short-lived so slower-growing trees can be planted alongside them to combat this. 
  • Density
    • Tree and shrub density influences wind protection. Therefore if you have a denser tree cover, less wind will penetrate through the shelterbelt. 
    • Shrub species protect the area closer to the ground surface. 
    • Coniferous trees with dense, year-round foliage can greatly help protect the surrounding area from wind and snow. In contrast, deciduous trees and shrubs lose their foliage in the fall so during the cold months deciduous shelterbelts are less effective.
  • Tree age
    • Younger trees also protect the area closer to the ground surface. Older trees protect the area higher above the ground surface. 
  • Tree placement
    • Shelterbelts are very effective with five rows of tree and shrub species. If there is not adequate space for five rows, it is better to plant less rows, such as three, instead of crowding more rows in a tight space. One must allow full growth of a shelterbelt for it to be most effective so overcrowding is never recommended. If three rows would even seem to be too tightly crowded, a two-row shelterbelt is an appropriate alternative for such a crowded area. It is even better if the trees in each row are staggered from the other row. This allows for optimal protection. Conifers are recommended for these two or three row shelterbelts. One row shelterbelts are also an option, depending on its purpose as well (i.e., planted on arable land).
Image 1. One possible design for a shelterbelt: a field shelterbelt consisting of common caragana.
Source: Colin Laroque

Developing a sketch of the area 

Creating a sketch of the shelterbelt area can greatly help the planning and designing process. Important considerations include:

  • Noting the orientation on the sketch pad (e.g., north arrow)
  • Identifying trouble areas needing mitigation by the shelterbelt such as areas of snow buildup, flooding areas, steep slopes or lagoons
  • Noting the wind directions wishing to be protected from
  • Locating current or future buildings and structures present in the area
  • Identifying distances between structures and the shelterbelt area
  • Noting property lines, powerlines and utility structures, fences, and roads
  • Locating existing trees and other plants
  • Noting landscape features such as hills, wet areas, grassy areas and crops
  • Sketching in the new locations of the future shelterbelt, noting the species selected, the spacing, and the length and width of shelterbelt rows.

Selecting tree and shrub species

Overview

Soil and climatic conditions are normally the largest factors in determining which species are suitable for a shelterbelt. Native species are normally best since they are adapted to these conditions. It is often recommended to plant various plant species in a shelterbelt to promote diversity. You also want to focus on species that can thrive in your specific soil zone. In Saskatchewan, there are 4 soil zones: Brown, Dark Brown, Black and Grey. Different plant species survive better in different soil zones and it is beneficial to determine these species for your zone. 

Usually 2-5 species of shrub and tree are used in a shelterbelt, but of course this can change. Shelterbelts can consist of only 1 species, to more than 5.  

Soil and climatic conditions are normally the largest factors in determining which species are suitable for a shelterbelt (alongside the purpose of the shelterbelt).

Native species are normally best since they are adapted to these conditions. However, non-native species have been used successfully in shelterbelts as well.

It is normally recommended to plant various plant species in a shelterbelt to promote diversity. Diversity is beneficial in all natural environments including shelterbelts. More benefits and services are provided by multiple species of tree and shrub. There is also less of a chance of a massive loss of biomass from events such as disease, insect infestation, fire or drought. This is because different species react differently and have different adaptations to withstand such events. 

Soil zones

Which trees and shrubs to select for your shelterbelt mainly depend on the climate of the area and the purpose of the shelterbelt. Site characteristics such as nutrient level also play a role in helping determine which tree and shrub species can thrive there. 

You also want to focus on species that can thrive in your specific soil zone. Soil zones are large geographical areas where one soil type dominates. In Saskatchewan specifically, there are 4 soil zones: Brown, Dark Brown, Black and Grey. Brown is found in southern Saskatchewan, Dark Brown is found around the Saskatoon area, Black is found around Prince Albert and Grey is found more north but below the Boreal Forest area of the province. Different plant species survive better in different soil zones because soil zones have different characteristics regarding soil moisture, nutrient regime, pH, climate, etc. The colours Brown, Dark Brown, Black and Grey represent the soil organic carbon (SOC) contents of the soil and their relationship to the climate. The southwest corner of the province has the lowest moisture levels and this results in less available water for plant growth and soil formation and this leads to lower levels of SOC in this area. Going further north (and northeast), the precipitation levels continually increase and this results in more plant mass able to be produced and more SOC available to be present in these soils. Overall, as temperature decreases and precipitation and available water increases going north, SOC increases.

  • The southern Brown soil zone of Saskatchewan covers the Mixed Grassland Ecoregion of the larger Prairie Ecozone. This ecoregion area is the most arid area in Saskatchewan; it is a semi-arid area with the lowest mean annual precipitation (MAP) and the highest mean annual temperature (MAT). This means that drought tolerant plants will do well here but other plants not tolerant to drought may not. The dominant vegetation in the area is grasses. Large trees and forest areas that require vast amounts of water do not thrive here like in other areas, but they can be successfully planted in shelterbelts if they are monitored and watered sufficiently. Brown Chernozemic soils are the most dominant soil type but soils of the Solonetzic Great Group are also common. The soils here are high in nutrients and great for agriculture.
    • Caragana (Caragana aborescens) is a shrub introduced from Siberia. Caragana can grow up to 5 m tall and is very dense and therefore efficient at trapping snow and controlling ground-level wind. It is capable of growing on nutrient-poor soils. Caragana likes full sun, is very drought tolerant and grows best in well-drained areas (e.g., sandier soils). It will not tolerate prolonged flooding and poorly drained soils. Therefore, Caragana is very suitable for the Brown soil zone. Recommended spacing is 1 foot, or 3 feet if under plastic mulch. Its lifespan is 50+ years. Note, seeds can also easily spread if not controlled. 
    • Of the woodland areas that are present, trembling aspen and shrub species are popular. Other species present include choke cherry, hawthorn, silver buffaloberry, northern snowberry, common lilac, eastern cottonwood, green ash, balsam poplar, Alaska willow and white spruce.
    • These species are adapted to the semi-arid climate and do well in this type of soil. 
  • Next, the Dark Brown soil zone around Saskatoon and down towards the Regina area covers the Moist Mixed Grassland Ecoregion of the Prairie Ecozone. This Ecoregion is still characterized by the gross Prairie Ecozone characteristics, but has a more subhumid continental climate, an increased amount of woodland area, a slightly lower MAT and a slightly higher MAP level. Soils here are still rich in nutrients and this is where Dark Brown Chernozemic soils dominate.
    • Species that thrive in this soil zone include choke cherry, hawthorn, silver buffaloberry, northern snowberry, eastern cottonwood, green ash, and peachleaf willow. Caragana is also applicable to this soil zone.
  • The Black soil zone, found more north near Prince Albert and down towards Yorkton, covers the Aspen Parkland Ecoregion of the Prairie Ecozone and the Boreal Transition Ecoregion of the Boreal Plain Ecozone. This area is overall a mix of farmland and forest with many deciduous species. This area is considered to have a humid continental climate and has a higher MAP level and lower MAT the higher north you go. Black Chernozemic soils dominate, with Luvisolic Order soils found in higher elevation areas of the Aspen Parkland.
    • Trembling aspen and understory shrubbery are prominent in the Aspen Parkland area and species in the Boreal Transition area include many aspen and white spruce along with some jack pine, black spruce, balsam poplar, etc. More species include red-osier dogwood, chokecherry, Saskatoon berry, snowberry, bur oak, and willow.
  • Finally, the Grey soil zone of Saskatchewan is found mainly in the Boreal Transition and the Mid-Boreal Upland Ecoregions of the Boreal Plain Ecozone. This geographical area is the most north of all mentioned, and this results in this area having the most precipitation and lowest MAT. This higher precipitation level  results in organic matter and nutrient leaching from the soils by this water, which results in Grey type soils. This increased water level also means that greater biomass can be supported; therefore, this is the most forested of the areas mentioned. Leaching of the soils and the fact that the carbon in the environment is taken up by the plentiful trees in this area both contribute to the lower levels of SOC as well.
    • Species to be planted in shelterbelts in this area should be able to withstand lower temperatures and higher precipitation levels. Species that thrive in the Boreal Transition area include trembling aspen, balsam poplar, white spruce, balsam fir, willow, some black spruce and tamarack.

Spacing recommendations

Overview

There are different spacing recommendations within shelterbelts for different species of tree and shrub. In general terms, spacing between trees in a row is 2-5 m, and spacing between shrubs in a row is 1-2 m. However, this can vary with shelterbelt purpose, species used, planting site conditions, etc. 

There are different spacing recommendations within shelterbelts for different species of tree and shrub. For example:

  • Caragana should be spaced 1 meter apart
  • Chokecherry, pincherry, hawthorn, red elder, red-osier dogwood, silver buffaloberry, snowberry and lilac should be spaced 1 meter apart 
  • Trembling aspen should be spaced 2 meters apart
  • Bur oak, cottonwood, green ash, hybrid poplar and willow species should be spaced 2.5 meters apart
  • Spruce species should be spaced 3.5 meters apart 
  • As a rule of thumb: 
    • Deciduous trees are to be planted 2-3 meters apart 
    • Deciduous trees and shrubs are to be planted 2 meters apart 
    • Coniferous (evergreen) species are to be planted 2-3 meters apart 
    • Hybrid poplars, hybrid larches, poplars or spruces are to be planted 2 meters apart
    • In general terms, spacing between trees in a row is 2-5 m, and spacing between shrubs in a row is 1-2 m. However, this can vary with shelterbelt purpose, species used, planting site conditions, etc. 

Space required for shelterbelts in crop areas can be reduced by planting only a single row shelterbelt. However, the spacing between plants in the single row should be adequate (i.e., whatever is necessary for the species).

Shelterbelt tree calculator

Please see the AAFC Shelterbelt tree calculator in order to determine the number of trees required for your specific shelterbelt and the amount of area they will occupy. 

Drip irrigation for shelterbelts

Decide whether you would like to use drip irrigation as a means to water your shelterbelt. There are many benefits to drip irrigation. See “HFIT” for more details. 

Planting your trees and shrubs

Overview

Choosing your area is very important when planting a shelterbelt. Soil should not be frozen during planting time, and soil should not be completely waterlogged nor completely dry. The area should also be clear of obstructions such as power lines, other buildings or even underground services. After deciding on your area, make sure to prepare the area a few days before planting, such as weed and debris removal, loosening up the soil. The next steps are digging the hole, planting your tree or shrub, and then caring for and watering the area. See “planting” (page 2) for more details on planting your shelterbelt. 

This information is for after you have obtained your seedlings and now want to plant them: 

  • Choosing your area
    • Many farming practice sources recommend to never plant your seedlings into frozen ground – instead wait during Spring when temperatures are consistently above zero so as to not risk a major frost. If it helps, this is also the time when gardeners plant their gardens. In contrast, some professionals believe that it is acceptable to plant seedlings on a below-freezing day or while there is still a chance of frost as long as the roots remain at an appropriate moisture level, which promotes survival. 
    • Be sure that your soil is not completely waterlogged nor extremely dry. If one of these is true for your site, wait a few days or a week to plant your seedlings. 
    • Make sure the area where your shelterbelt will be planted is clear of obstructions such as powerlines, other buildings or even underground services that can be dangerous and/or inhibit the full growth of your trees. Objects around the shelterbelt area must also not block sunlight from reaching the seedlings. 
  • Preparing your area
    • Make sure to begin area preparation a few days before scheduling to plant your seedlings. 
    • Remove weeds in the shelterbelt area and any other debris such as dead branches. A 12-inch radius around the seedling area is sufficient. 
    • Loosen up the soil in the area if it seems to be too compacted. This can be done by digging with hand tools, rototilling, cultivating, etc. 
  • Digging your holes
    • See “planting” on page 2 for more details.
  • An optional step is to amend your soil. Amending means to change or make better; soil can be improved with nutrient additions or by adding bone meal into the hole where you will plant your seedling. Bone meal can be bought in packages at gardening stores and applied by following package instructions. 
  • Planting your tree
    • Water and fill the hole
    • Water the area around the seedling
    • Protect your trees from pests
    • See “planting” on page 2 for more details.

Additional Information:

References:

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