Home ยป The risk of dangerous “zombie” trees is growing due to drought conditions in British Columbia.

The risk of dangerous “zombie” trees is growing due to drought conditions in British Columbia.


They exist within our society and have the potential to attack without warning.

Arborists are raising concerns about trees known as “zombie trees” that present a hidden danger. These trees may appear unharmed following extreme weather events like storms or droughts, but they actually suffer internal damage and can unexpectedly collapse.

Experts say that due to severe drought conditions in British Columbia, there may be a higher occurrence of dangerous zombie trees this year. Identifying and eliminating these trees is crucial in order to safeguard both infrastructure and individuals at risk.

“What ends up happening is the trees are forced to use their stored energy to combat the drought, and they’re unable to produce excessive stored energy to fight back against pests, against storms,” said Scott Gardner, district manager at Davey Tree Expert Company.

A man in reflective jacket
According to Scott Gardner, district manager at Davey Tree Expert Company, it can be difficult to identify zombie trees as they may have a complete covering of leaves. (CBC)

“He stated that we will witness one of two outcomes: either a disastrous failure once the rain begins, or a sudden demise.”

Gardner frequently encounters zombie trees in Metro Vancouver, although it can be difficult for someone without expertise to recognize them.

He mentioned that he searches for indications of decay or the presence of mushrooms at the base of a tree, as well as irregular growth patterns, harm, or deterioration in the top part of the tree. However, certain trees that are in a zombie-like state can still possess a complete and lush upper canopy, which can make it difficult for individuals to promptly detect any problems.

“Just today, we had two trees that fell on people’s houses and both of them had a full canopy of foliage,” Gardner said. “There was root, rot or decay in the root and the tree failed at the base. These are perfect examples of trees that are zombie trees and to the untrained eye would look completely fine.” 

On the evening of October 24th, a large tree resembling a zombie toppled onto a residential area in North Vancouver.

Karen Tregillas, a resident of the Indian River area in North Vancouver, described hearing a loud snap and crash followed by a thunderous boom. She discovered that the top of a tree had been flung approximately 25 feet away from her sliding door.

The tree in question was a Western Hemlock. It had white fungus in its heartwood, which according to Gardner, makes it a zombie tree. 

That evening, powerful winds swept through the southern coast of B.C., causing power outages for numerous residents. B.C. Hydro reported that certain blackouts occurred as a result of trees collapsing onto transmission lines.

A crusty dead tree trunk
Zombie trees have deep cracks and splits through the bark that extend into the wood of the tree’s trunk or limbs. (CBC)

Tregillas mentioned that the vehicle had forcefully broken the chain-link fence. He had expressed concern about the tree earlier, as he would observe its lifeless appearance from his bedroom.

Tregillas mentioned that she refrains from taking her dog for walks in the woods during windy weather, and she makes an effort to be especially careful even on calm days.

“She mentioned that she has experienced being outdoors during moments of complete silence, resembling the stillness of night, only to suddenly hear the sound of a massive tree falling.”

Arborist Gardner advised that individuals should remain vigilant for zombie trees. It is important for people to observe the trees on their land and take note of any signs of decay, cracks in the bark, or abnormal discoloration of the foliage.

WATCH | How to spot a zombie tree:

Concerns arise due to the presence of ‘Zombie’ trees caused by drought conditions in British Columbia.

13 hours ago

Duration 4:03

Featured VideoThe lack of rainfall in B.C. is causing the appearance of what Scott Gardner, who manages a tree care and removal company called Davey Tree, refers to as dangerous “zombie” trees. These trees were once healthy but have become weakened due to extended periods of water scarcity, and they now pose a risk to the environment and the safety of the public.

He advised that it is advisable to consult certified professionals for assistance if any signs are observed.

As the storm season becomes more active, the province expects an increase in power outages due to weakened trees caused by severe weather.

Susie Reider, spokesperson for B.C. Hydro, stated last week that there is a higher chance of experiencing major power outages during a windstorm.

Reider mentioned that trees that have been weakened by drought and related illnesses may be more prone to wind damage. It is anticipated that a significant amount of dead or damaged trees and branches will fall, resulting in power outages.

Based on the given statement, teams are sent out to examine trees and other tall plants that are growing close to BC Hydro’s infrastructure in order to detect any possible issues.

Source: cbc.ca