A “stupendous sexual show” has been taking place this spring in the Cowichan Valley and beyond, but what it all means for the much-loved arbutus is unclear, says forest ecologist Andy MacKinnon.

Arbutus trees have been bursting with more white, urn-shaped flowers than MacKinnon can remember.

“It’s an extraordinary flowering year,” says the author of several guide books, including the iconic Plants of Coastal British Columbia. “On some of the trees, the weight of the flowers is so heavy it’s bending the narrower branches. And the smell in the air, which to my nose smells of buckwheat honey, is so incredibly sweet.”

The way it works, pollinators such as bees fertilize the flowers, which then develop into clusters of fruit containing the seeds. The fruit is consumed by birds and other animals, which then distribute the seeds through their droppings.

MacKinnon offers two potential explanations for the mass flowering event.

“Such extraordinary flowering is either a really good sign of really healthy, happy plants or just the opposite, a last-gasp attempt for the trees to maximize their flower production because they sense an oncoming decline.

“I’m an optimist by nature so I think the conditions are just right this year…and not the death rattle of arbutus trees.”

Arbutus suffer from time to time from a native fungal leaf blight, including in 2021. Climate change could be making matters worse, especially for those trees located on rocky, shallow soils at the northern end of their range.

The blight results in arbutus dropping their leaves, and if the disease persists it can actually kill the tree. In the US, arbutus is known as madrone.

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— Larry Pynn, May 26, 2025