Intro
As spring arrives in the Okanagan and other parts of British Columbia, trees are beginning to wake up from dormancy. But the effects of this past winter—unseasonably warm and dry—are already setting the stage for a potentially challenging growing season.
At Microbe Tree Service, we’ve seen firsthand how weather patterns influence tree health. This year, homeowners should be especially vigilant. Below, we break down what to expect, the pests and diseases to watch for, and how our certified arborists can help.
A Warmer Winter Means More Stress for Trees
Winters in our region typically help reduce pest populations and give trees time to rest. But this past season didn’t follow the usual script. With less snow and fewer freezing days, trees haven’t had the recovery time they need, and many insects and pathogens that would have been suppressed by cold weather are likely to emerge in larger numbers.
Key Concerns
- Higher pest survival rates: Insects like the Bronze Birch Borer and Mountain Pine Beetle are more likely to thrive after a mild winter.
- Increased fungal infection risk: Dry conditions reduce a tree’s ability to fight off fungal diseases.
- Cumulative drought stress: Trees already affected by previous dry summers may be especially vulnerable this year.
Pests and Diseases to Watch for in Spring
Knowing what signs to look for can help you spot problems early and take appropriate action.
Bronze Birch Borer (Agrilus anxius)
- Affects: Birch trees, especially if already stressed
- Symptoms:
- D-shaped exit holes in bark
- Thinning or dying upper branches
- Zig-zag tunnels beneath the bark
- Management: Early-stage infestations may be treated with strategic pruning. Advanced cases often require tree removal to prevent spread to nearby birches.
Mountain Pine Beetle (Dendroctonus ponderosae)
- Affects: Various pine species
- Symptoms:
- Small pitch tubes (resin blobs) on trunk
- Wood beneath bark may have blue staining from associated fungi
- Management: Heavily infested trees pose a threat to surrounding healthy pines and should be removed promptly.
Diplodia Tip Blight & Rhabdocline Needle Cast
- Affects: Primarily conifers, especially pines and Douglas-firs
- Symptoms:
- Tip dieback and browning of new growth (Diplodia)
- Yellow or reddish-brown needle discoloration followed by premature needle drop (Rhabdocline)
- Management: Proper pruning can improve air circulation and reduce infection risk. Fungicide applications may be recommended in some cases.
Why Proactive Tree Care Matters
Preventive care is often the best way to extend the life of your trees and reduce long-term costs. At Microbe Tree Service, our ISA Certified Arborists specialize in identifying risks early and recommending tailored solutions.
Our Services Include:
Pruning for Health and Structure
- Removal of weak or diseased limbs
- Shaping to reduce wind resistance and improve air flow
- Supporting the tree’s natural growth patterns and defenses
Tree Removal When Necessary
- Trees that are structurally compromised or beyond recovery due to pests or disease
- Safe and professional removal to protect nearby structures, plants, and people
