Arborists near you

The roles overlap, and many tree companies employ arborists, but they answer different questions. A consulting arborist sells advice rather than tree work, which makes their opinion easier to trust when a decision is costly or disputed. When the company that diagnoses a problem also earns the fee for the removal it recommends, a second opinion on a large, healthy-looking tree is reasonable.

Ontario is the province where arboriculture is a formal trade. Arborist (444A) covers the transplanting, maintenance and removal of trees, and Skilled Trades Ontario grants a Certificate of Qualification to apprentices who complete their training and pass the exam. Because the trade is non-compulsory, the certificate is a mark of training rather than a licence to work, and plenty of uncertified people still offer tree care.

Across Canada, the most widely recognized credential comes from ISA, the international association for arboriculture, which certifies arborists by exam and requires continuing education to keep the credential. It also offers more specialized qualifications, including one in tree risk assessment, and some consultants hold a further consulting designation from a professional society. Ask for the credential number and check it with the issuing body, and ask whether the certified person will visit the site or only sign the paperwork.

A tree risk assessment weighs three things: how likely the tree or a part of it is to fail, what it would hit, and how serious the damage would be. A dead limb over an empty meadow is a low risk; the same limb over a driveway or a child's play set is not. Most assessments begin with a walk around the tree from the ground. When something looks wrong, an arborist may go further, climbing to inspect a fork, digging carefully at the root collar or using instruments that measure decay inside the trunk. The result should be a written recommendation, which may be to prune, cable, monitor or remove.

In Toronto, a permit is needed to injure or remove a tree protected by the City's by-laws, which cover private trees 30 cm or more in diameter, measured 1.4 m above the ground, and City-owned trees of any size. An arborist report is required with an application to remove or injure a tree. It sets out the tree's location, species, size, condition, structural integrity, disease, infestations and health, along with the proposed work and the tree protection measures. Pruning doesn't need a permit when it follows good arboricultural practice to keep the tree healthy.

In Montreal, felling a tree on private property requires a permit, with the conditions set by each borough, and many other municipalities have their own tree by-laws. Wherever you are, a useful report is specific: measurements, photographs, what was inspected and how, and a clear recommendation with its reasons. A report that says only that a tree should come down gives an approving officer, or a neighbour, little to go on.

Construction damage often kills a tree slowly, with the decline showing years after the crews have left. The City of Toronto lists building, demolition, excavating, driving vehicles and equipment, storing materials, equipment and soil, and creating waste among the activities that can harm a tree's leaves, branches, trunk, roots and soil. It defines the tree protection zone as the area around a tree that must be protected during construction, and if any work on site, including access or storage, will affect that zone, a permit to injure or remove the tree is needed. The City recommends consulting an arborist to assess the site and measure the zone.

Where a permit is involved, the site plan shows the tree protection zones to scale, with the protection distances and hoarding labelled, and the hoarding goes up as approved before the permit is issued. A tree protection plan must be prepared by an arborist or in consultation with one.