Drought causing stress on local trees

With this summer being one of the driest on record in recent memory, the lack of rainfall could have long-term effects on the city’s trees.

With this summer being one of the driest on record in recent memory, the lack of rainfall could have long-term effects on the city’s trees, says a local arborist.

Rob Hughes, supervisor of parks operations with the City of Victoria, said this is the worst season for drought stress on trees in the 30 years he has worked in Greater Victoria.

“As far as mature trees on the boulevards, certainly we’re seeing what’s being seen throughout the lower Island, just drought stress that’s visible on the leaves,” Hughes said. “If you go down most streets in Victoria now, we’re seeing some early desiccation of the leaves, so early fall colour and leaves are starting to drop. They’re most noticeable on the ground.”

He said the trees that have been most affected by the drought are birches, beech trees, katsura, and evergreens like the western red cedar that require a higher moisture content in their soil and can’t stand long periods of drought.

According to Environment Canada meteorologist Matt MacDonald, Victoria is having an exceptionally warm and dry summer.

“It’s the driest June, July, August on record. We’ve only seen 16.4 millimeters this year and that explains the extreme drought,” said MacDonald.

From Aug. 1 to 25, Victoria has seen 1 mm of rain, making it the fifth driest August on record with a mean temperature of 18 C.

But that is expected to change with a storm set to hit Victoria bringing an estimated 40 to 60 mm of rain over the weekend.

While the city can’t do much for mature trees, it has increased the number of tanker trucks used to water the newly-planted trees. They currently have four tanker trucks along with a fifth that works part-time.

But Hughes said the drought could have long-term effects on trees, especially in the spring when they start to leaf out again.

“There may be an increase in the next few years of trees showing signs of being infected with decay pathogens,” Hughes said.

“We’re able to fill up our tanker trucks with CRD water and go around and water our newly-planted trees. It’s all dependant on weather and hopefully with the forecast for this weekend, we do get some.”