While the City of Kamloops celebrates Arbour Day with plant-a-tree programs, one Westsyde resident is heartbroken after discovering her six backyard trees have been poisoned.

Carole Watson has been living at her home for 21 years and always enjoyed her three Chinese elms, two birches and maple tree.

But last week, her visiting son found holes about an inch in diameter drilled around the base of the trees.

Upon closer inspection, they discovered someone poured diesel into up to 30 holes per tree. She said she has no idea how long the holes have been there.

"I could smell the diesel before when I was painting my fence, it gave me a headache," said Watson.

An arborist inspected the trees and told her something that had become obvious: someone had done it deliberately. The company added they'd never seen anything like it before.

"The shock of it. I mean who would come into my yard and do this deliberately?" said Watson. "I've hardly ever locked my gate. I have an alarm system for inside my house because I always think there's more you can steal inside the house. I just never thought that I'd have a problem and someone would actually do this."

The thought of losing the shade, privacy and beauty of her trees, especially in the fall when leaves turn a golden hue, caused Watson to choke up.

The arborist said the trees would have to be taken down since they've become a liability and provided an estimate of $20,000 to do the work. The yard's fencing and a shed will have to be removed before the work can be done, she said.

Her insurance company said it would cover no more than $1,000 per tree.

Watson's part time salary from Sears will not cover the cost so she said she'll try to secure a personal loan.

Meanwhile, police have confirmed they're looking into the incident but would provide no details because it's an ongoing investigation.

Backyard neighbour Leann Wolfe, who lives with her son, said she's not sad to see the trees go because they're constantly having to pick up the leaves. She has no trees in her own yard.

She said police spoke to her about the incident.

"I know I didn't do it," she said. "No way I'd want anything like that to happen. It's not right."