Garry oak tree felled due to root rot

Oak Bay staff removed a tree from Oliver Street, the second downed in the community this month

A Garry oak on Oliver Street came down today after municipal staff discovered root rot. Photo courtesy Oak Bay Parks

A Garry oak felled on Oliver Street succumbed to root rot, according to a municipal arborist.

“I felt personally it was like losing a couple of old friends… we didn’t know they were sick,” Oak Bay Mayor Nils Jensen said Friday, as the tree came down.

It all started with a lean, he said, then a truck hit a branch.

“That’s what set off alarm bells, then when they did the investigation, that’s when it became fairly evident,” Jensen said.

“It had begun to slowly lean over the road and a truck clipped one of the larger branches,” confirmed Chris Hyde-Lay, manager of parks for Oak Bay. “We felt the tree had moved at the base.”

A staff arborist did a root collar exploration, trenching down to the structural roots, where he discovered shoestring root rot, or Armillaria.

“It’s pretty easy to diagnose, but it is a root disease so you don’t really see any crown symptoms so the tree can look really fine,” Hyde-Lay said. “It’s unfortunate because a tree like that just adds to the treescape of Oak Bay.”

common to many tree species but Garry oak is one of those prone to it, triggered by multiple stressors, including age.

“It’s always in the soil and if the tree becomes stressed the root fungus is opportunistic and takes advantage,” Hyde-Lay said.

Oak Bay Parks has tracked the largest of its Garry oaks since 2013 and describes the urban forest here as “healthy.”

“For the most part our urban forest is healthy but I would describe it as mature, to parts of it over-mature,” he said.

It is the second large oak removed this month, Hyde-Lay said. Another removed on private property on Monterey Avenue near and Hampshire Lane after it was also discovered slowly shifting.