Trees in the city cultivated as opposed to trees in nature, which are not purposefully planted or cared for. Trees where people live and work need to be treated differently than trees in a forest. Tree safety is an aspect of home ownership that is often overlooked and unregulated.
There are rules, standards, codes and laws governing the safety of your home, both in its construction and maintenance. The same does not apply for trees surrounding your home or on your property. Only in extreme cases will the city step in and force safety compliance for owners of hazardous trees. It’s up to owners to check on the vitality and safety of their trees so they do not threaten neighbours and their property. Large trees growing in densely populated urban environments are a greater threat to people and property beneath them than rural or park trees. The amount of people and property within the reach of tall trees in a city make their presence a concern for everyone near them. Trees of all ages and heights can fail for a number of reasons. High winds, drought, pathogens, irrigation, nearby construction and neglect are some obvious factors which can cause a tree to fail immediately or slowly over years. Predicting which trees will withstand extreme stress is more science than art.
Occurrences of severe weather in Ottawa have increased over the last 10 years. More freeze/thaw cycles in winter, dryer summers, high winds and now insects (mainly the Emerald Ash Borer) all impact trees’ health and safety.
Making your trees safe and healthy can begin with keeping a calendar for leaves opening and falling each year. If your trees’ leaves open later and fall earlier than trees in your neighbourhood your trees are in decline. If you just moved into your new home look your trees over carefully and make notes of any previous failures. Its normal for home buyers to have a prospective home inspected. I suggest you have the trees on the property inspected also. New owners can be shocked when faced with an unexpected expense to fix or remove a mature tree.
Lawnmowers and trimmers can forever damage trunk bark. Create a 4’ – 6’ radius around the trunk. Remove the grass and replace it with wood chips. This will provide an equipment barrier and is aesthetically pleasing. Watch for cracks and splits in the trunk and large branches of the tree. Mark the observation on your calendar. Holes give access to water and ice, insects and animals. Water that stands in holes causes rot and decay. Homes for squirrels, birds and raccoons begin with holes that they enlarge for their growing families. These animals dig out the inside of the tree and reduce structural strength. Watch for mushrooms, they are a sign the tree is rotting inside. If Woodpeckers frequent your tree it means lots of insects are inside. Those insects are eating the tree and making it weaker and increasing the likelihood of failure. If you notice your tree is now leaning, look around the tree to see if the ground is heaving. Major roots may have been injured, cut or died. The bigger the lean the more likely the tree has to be removed. When you can see patches of bark falling off the branch or trunk act promptly to remove the branch or tree. Bleeding sap indicates a crack or split or some physical failure in the tree. Ants marching up and down the tree means they have chosen your tree for food and protection. Record your insect finding and see what damage they are doing. Look also for dead, dying, diseased, broken and hanging branches. If they are larger than 1” in diameter they have them removed. Its normal to keep records of when your roof was last replaced or when you purchased a new furnace. Keeping a calendar to track the stressors that affect your tree is easy.
For the actual work and maintenance of a tree, an Arborist is essential. Tree work is inherently dangerous. Arborists thin and prune branches to reduce weight and water usage, open vistas, and clear away branches that interfere with electricity and communications wires. Arborists safely treat and remove trees and provide hazard assessments to determine the removal of trees larger than 20” in diameter to satisfy City of Ottawa Distinctive Tree Regulations.
Large majestic trees are of special safety concerns because of their massive height and weight. Reducing the end weight in the canopy reduces stresses on the trunk. Certain species of trees are more likely to do harm because they are prone to fail. Manitoba Maples often break under their own weight and excessive leans. Poplar branches are weak and often break and fall. Both tree species grow rapidly and are weak wooded. It is not safe to have either tree grow in an urban environment.
Trees around a home provide aesthetic beauty, air borne particulate filtration, air conditioning and placing the mind at ease. Trees benefit both owners and neighbours. But there is no bar code on the trunk to indicate a best before date. Through ongoing care by both the owner and professionals, trees will grow healthier and safer.