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Tree Care

Tree CareLife for boulevard trees is hard. When a boulevard tree is contending with challenging conditions it can become stressed, weak and susceptible to insects and diseases. 

Trees on City boulevards often encounter damaging or life-threatening conditions specific to the urban environment. These include limited space, lack of sufficient water, poor soil conditions, human damage, high temperatures, drying conditions, air pollution, insects and diseases.

Many tree health issues can be resolved by following these general management practices to improve tree health:


Lack of water is the single greatest factor that leads to the death of newly planted trees. During dry spells, a hose that is left trickling should be used once a week to soak the root area for one to two hours. Avoid short, frequent watering which promotes a shallow root system. Infrequent, but deep soaking preferably during the early morning hours is recommended. Water absorbing roots are located within the first 25 cm of the surface and extend outward well beyond the canopy dripline (the dripline is the ground that lies below the outermost reaches of the tree branches). Be sure to respect the summer watering restrictions.


Mulch, which usually consists of chipped wood and bark, insulates the soil, retains moisture, prevents soil compaction and reduces lawnmower damage. Maintain a level grade of mulch around the tree to a depth of 5 to 10 cm (2 to 4 inches); do not mound mulch. Make sure to keep it a few centimetres away from the trunk to avoid rodent habitation and other tree health complications. Spread the mulch wide to the drip line. 


Once approval is received from the City's Parks & Open Spaces Section to ensure the tree has not been fertilized already, choose tree fertilizer stakes to feed your tree. Apply these stakes into the ground as soon as the ground thaws in the spring, and water the tree throughout the growing season. This type of fertilization method slowly releases nutrients to the tree’s roots. For fertilizer quantities, follow the directions on the label. Do not fertilize your tree in late summer; it will stimulate growth, preventing the tree from preparing itself for winter. 


  • Do not conduct any unnecessary excavating, grade changes, soil compaction, root cutting or hard surfacing around the trees. These activities destroy vital roots, which may lead to the decline or death of a tree. 
  • Do not dig under or around the tree to at least as far as the branches spread. Doing so will damage the fine feeder roots required to provide nourishment for the tree and could destabilize it.
  • Do not store or dump material under the tree to at least as far as the branches spread. This material could be toxic or lead to soil compaction, depriving the tree of air and water. Refrain from using salt or herbicides around trees.  
  • Do not prune without approval from the City's Parks & Open Spaces Section. See the Pruning Guide for more information.
  • Do not damage a tree in any way. Do not mark, cut, debark, deface, break, injure or apply harmful or toxic substances. 
  • Do not post any signs or attach objects to public trees. Nailing or tying things can injure a tree and make it prone to insect and disease damage.
  • Do not destroy or remove a public tree – it constitutes an offence. Instead let the City's Parks & Open Spaces Section know of any concerns and they will come and assess it

The province of Ontario instituted a cosmetic pesticide use ban effective April 22, 2009.

Download our Tree Care Guide Adobe PDF, 1 Page, 2 MB

Call the City's Parks & Open Spaces Section (Dispatch) at 625-2195 to report any problems. Visit Tree Protection Standards to learn methods for protecting trees during construction.