Frequently Asked Questions

FREQUENTLY ASKED QUESTIONS BY THE CONSUMER

This section is constantly evolving. Currently, we have included some answers that frequently come up. Many of the questions we receive can be answered by consulting our brochures, which are available for free under the “Centre de documentation” menu.

Myths and realities about trees

While trees can generally take care of themselves in forests, in urban environments such as your yard or community, trees need protection and proper care. Each year, these persistent and insidious myths are responsible for many costly and sometimes dangerous mistakes in tree care.

Sources:

Myth: Trees can break sewer pipes.

The roots are attracted to sewer pipes and can break and perforate them.

• The reality…

  The underground pipes are often broken by wear over time, by weather action, or by freeze/thaw cycles. They can be broken, defective, misaligned, and non-watertight. Tree roots are unable to split pipes. The roots present in the drains are small and tender, and they hang from the top of the pipe. They can take advantage of existing leaks that let liquid escape. Without these leaks, drains covered with watertight sand seals are not attractive to roots. When there are open and non-watertight joints, nourishing gases escape from the network and slowly rise to the surface. Roots can therefore gradually develop towards the pipes by taking advantage of the leaks. They penetrate through the existing openings (cracks).

Myth: Roots can break the foundations of a house

• The reality…

  Tree roots cannot survive in sterile environments like concrete, and they will never try to penetrate the walls of a foundation. On the contrary, roots will seek out moisture and could enter pipes (or foundations) that have leaks or cracks in search of moisture.
  
  Roots are devoid of water detectors. They don't need them because they grow and proliferate where they enjoy favorable conditions. Trees, therefore, do not waste their energy seeking water. Root growth is opportunistic. The tree normally spreads and distributes its roots under the soil surface, where there is air, water, and minerals. Therefore, it has no interest in invading the soil too deeply. More than 90% of tree roots are found in the first fifty centimetres of soil. A tree's roots can spread over a radius ranging from one to two times its height. Several factors can cause cracks in a foundation. The use of certain soils to backfill buildings, the transfer of surface water from roofs and driveways into storm drains, prolonged drought periods, as well as the removal of large quantities of earth in soils where trees are present. All these factors can contribute to retracting the soil and lifting the foundation, causing cracks.

Myth: As they grow, tree roots are capable of lifting sidewalks to develop.

Roots are often responsible for the lifting of sidewalks, paving stones, and driveways.

• The reality...

  Many sidewalks are broken or lifted by wear over time, by climate action, by freeze/thaw cycles, by the movement of heavy machinery (during snow removal), or due to poor construction quality. When breaking, sidewalks automatically lose some of their solid appearance. During the first stage of roots' growth, the new tissues occupy the space left free by the displacement of the sidewalk. These more or less gelatinous tissues are unable to exert pressure on anything. Instead, they mold to the objects they come into contact with. During the second and final stage of growth, the same tissues harden in their formation position and turn into wood. From then on, the sidewalk can no longer return to its original position. It is always preferable to avoid moving heavy machinery over sidewalks. When constructing a sidewalk, make sure the base is solid, deep, and stable. For a private sidewalk, it's better to bypass the roots.

Myth: Trees have deep roots 

Most trees start their life with a taproot - a straight tapered root that grows vertically downward and from which other roots grow. Over time, the roots will dig very deep into the ground and remain primarily vertical.

• The reality…

  Most trees do not have a taproot; they tend to be shallower than you think. While some trees have a taproot when they are young, after a few years, the main root system becomes widespread with primarily horizontal surface roots and only a few downward-growing anchoring roots.
  
  Tree roots need to be shallow to stay in the loose, aerated soil near the surface. They extend several times the width of the canopy. Root damage is a major cause of decline, death, breakage, or failure. Certain actions or phenomena like soil compaction, soil removal, root cutting, backfilling over roots, flooding, or drought could compromise the condition of the tree's root system and cause its decline.

Myth: Tree wounds need to be covered with sealant products.

Like animals, trees can be injured. Covering the wound with paint or filling a cavity with material will speed up and complete the healing process.

• The reality...

  Unlike animals, trees do not have a healing process. Healing means returning to a healthy state, repairing, or replacing injured tissues. Trees, with their rigid cell walls, are unable to heal injured or infected tissues. Instead, trees will cover or isolate damaged tissues rather than heal them. When the bark of trees is damaged, microbes attack the plant tissue, and trees respond by creating walls around the tissues. This process is called "compartmentalization" and occurs when the tree constructs four walls around the injured area to preserve the rest of the tree. The survival of the tree will depend on its success in compartmentalizing the injury.
  
  Research shows that sealant products do not stop decay or rot. Trees respond effectively to their wounds without additional chemical help. Therefore, one should not interfere with this natural process by applying house paint, wood preservation products, or heavy coats of any material to a wound. Keep your tree healthy, and it will take care of its injuries. In a short time, the surface of the wound will blend perfectly with the tree's bark.

Myth: Prune branches flush with the trunk. 

Pruning is often done to remove dead wood from a tree, to clear ground space, and to remove interfering branches or to balance weight. To ensure no stubs remain on your tree, cut the branch as close as possible to the trunk.

• The reality...

  The branch collar, which is the part of the branch that meets the trunk, must remain intact for the tree to stay healthy. Cutting a branch too close to the trunk removes the collar, which leaves the tree vulnerable to pests, decay, and disease.

Myth: Topping is a good choice.

When a tree becomes too large, it is appropriate to remove all the highest branches to ensure that the tree does not interfere with the view, sunlight, or surrounding structures.

• The reality...

  This practice called "topping" is completely unacceptable. It violates all accepted pruning practices. A topped tree is weak, vulnerable, and deprived of the nutrients from its leaves, leading to weak branches, vulnerability to pests, decay, and disease. Additionally, a topped tree is much more expensive to maintain, is not visually appealing, and has weakly attached branches that will grow even larger than the original branches and can break very easily, even in very light winds. Topped trees often need to be removed because they become dangerous.
  
  Whenever topping is considered, there are two acceptable alternatives:
  
  Contact a commercial member of the SIAQ to learn more about crown reduction (a safe alternative to topping).
  
  Remove the tree and replace it with an appropriate tree for the location.