Factsheet: Site selection and preparation

This factsheet walks through important considerations for choosing where to plant trees and how to prepare for planting in sites where conditions are less than ideal. It provides step-by-step guidance that communities can use to help ensure long-term tree survival.  

This factsheet was created to support small and rural communities who are just developing their urban forestry approaches and content might be helpful for municipal staff working in various departments such as public works, recreation or public health services.

Why does the right site matter?  

Communities should plant the right kinds of trees in the right places at the right times. Good planting sites are the foundation of successful tree planting.  

Choosing the right site and preparing the site before planting can help avoid costly challenges like premature tree removal and complicated maintenance. Additionally, choosing the right site will minimize potentially hazardous conditions and community safety concerns. Careful site selection and preparation can also allow for planting in areas that are traditionally not as well suited for planting, but which may be important for achieving community benefits. Community benefits can include climate resilience, easier access to nature and cooling shade, and better quality of life for all residents including equity-deserving groups. 

This factsheet covers two important processes. Site selection is choosing where new trees will be planted, while site preparation is the process of readying a selected site for successful planting. Careful consideration of both is crucial because the conditions of a planting site directly influence the establishment and long-term health of trees. 

How to select and prepare your site 

1. Consider your objectives for planting 

Start by defining the objectives of your planting project to guide and prioritize sites where trees could have the greatest impact. Consider broader community goals related to urban forest management, biodiversity, climate action and equity.  

Try a tool like HealthyPlan.City to help you identify areas with low canopy cover, high summer temperatures or high flood risk in your community, as well as how these areas intersect with populations that may be disproportionately impacted by these factors. 

2. Create a site inventory  

Conduct surveys of potential planting sites using tools like GIS (geographic information system mapping) combined with ground-based surveys (which can be done by driving or walking). Gathering community feedback can also help identify where new trees would be most beneficial. While surveying non-municipal lands, identify the landowners of the potential planting sites in your inventory. Recording planting sites in a site inventory can also aid future tree planting operations. 

For more information on the tools, you can use to create site inventories, review our Tools and technologies factsheet. 

3. Assess planting sites 

Site conditions vary widely across and within communities, making site assessment crucial before planting. Important factors to consider in your analysis include soil conditions, growing conditions such as water availability and access to sunlight, exposure, height and space requirements, physical limitations, and previous land use or history of the site. 

Soil 

Soil quality is vital to tree establishment and growth. Site selection and preparation requires consideration of both soil volume and composition.  

Soil volume refers to the amount of soil available for roots to grow. Ideally it is as large as possible to support root spread and depth. A good guideline is that trees should be planted in a soil volume of 0.6 cubic metres per square metre of the tree’s crown area at maturity (for more information, consult the Canadian Landscape Standard). 

Soil composition is the mix of air, water and nutrients in the soil. High-quality soil is typically a mix of roughly 25% water, 25% air, 45% minerals and 5% organic matter. Field or laboratory testing can help you determine soil composition, including pH and nutrient levels, organic content, and the proportion of different soil components (such as sand, silt or clay).  

Retaining existing soils, where possible, helps to preserve soil structure and microorganisms that support tree establishment. In sites with poor soil, remediation or replacement can improve tree establishment (this is covered in step 4 below).  

Water  

Trees grow best when they have access to an uncontaminated, consistent water supply and soil with good infiltration and drainage. It is important to assess how the sloping of the land and the soil conditions will influence water distribution and pooling. In dry conditions, irrigation or watering may be necessary—particularly during the first two years after planting.  

Exposure 

Urban planting sites can vary widely in their exposure to shade, wind, salt and cool or hot microclimates. Different tree species vary in their tolerance to these factors. When selecting planting sites, consider the location’s current or potential exposure to factors that could impact the survival of different species. 

For more information on selecting tree species, review our Stock Selection factsheet. 

Physical limitations 

When planning where and how to plant, it’s important to consider the size of the tree both at the time of planting and when it reaches maturity to understand the space required for healthy growth. Conduct an evaluation of elements above and below the ground that could affect the available space for tree growth. It’s also important to consider maintenance requirements and future accessibility to the site. 

Consider what’s above the site: 

Examples: signage, lights, traffic, power lines, sightlines, maintenance limitations 

Examine all above-ground site factors. How will growing trees affect traffic, buildings, utilities, sightlines and private property? What kind of spacing is there from other trees? Is there enough clearance from surrounding infrastructure? Is there anything there that will make it difficult to maintain the site? These are all important factors to plan for before planting trees. Remember to plan for trees to reach their mature sizes and consider how large trees would affect the area.  

Consider what’s below the site:

Examples: water pipes, gas lines, electrical infrastructure, artefacts or anything else of cultural or archaeological significance 

Examine all below-ground site factors. What underground infrastructure is there? For example, tree roots can grow into pipes and heave pavement. Check your municipal and provincial guidelines (use a resource such as Click Before You Dig) and check with utility authorities to see what’s below any planting site you’re considering. Note that different provinces have different utility regulations to examine before choosing a planting site.  

Previous land use or history of the site 

It's important to consider other factors about a site that may be hard to see, such as the history of land use and tenure of the area. When considering the history of the site, you could collect information on whether the site had been affected by forest fire, insect damage or weather damage in the past. You could also consider if the site had previously been used for industrial purposes, or as former marginal farmland. Community engagement can help you learn more about sites that may have cultural or historical significance. 

4. Apply strategies to improve site conditions, where needed 

After you’ve thoroughly investigated a planting site, you can identify any modifications needed to improve planting conditions. Site preparation can be an intensive process, so it’s important to plan carefully and seek professional advice before beginning. Some common strategies to improve site conditions include: 

• Adding soil or soil amendments to adjust soil composition, pH or nutrient levels and ensure sufficient levels of organic material (e.g., compost) 
• Removing rocks, pavement or other hard structures that could limit root development or affect water infiltration 
• Breaking up compacted soil to improve soil structure, increase nutrient uptake, and improve aeration and drainage 
• Decontaminating soil or completing other site remediation activities 

How to involve your community in site selection and preparation 

Community feedback is important for aligning planting objectives and priorities with local values and priorities. Engaging with community members can help you identify where trees should (or should not) be planted and to prioritize sites based on demand and equity considerations. 

Next steps 

Here are additional resources that can help you get started with selecting and preparing sites for tree planting: 

• Canadian One-Call Centres Committee, Click Before You Dig 
• Natural Resources Canada, A Guide for Successful Tree Planting  
• Natural Resources Canada, Site preparation science supporting tree planting 
• City of Guelph, Tree Technical Manual 
• Vibrant Cities Lab, Tree Planting - Urban Forestry Toolkit  

This resource was created in partnership by Tree Canada and FCM’s Green Municipal Fund for the Growing Canada’s Community Canopies initiative, which is delivered by the Federation of Canadian Municipalities and funded by the Government of Canada.