Risk of Oak Wilt rising in Eastern Ontario

Tom Donnelly
2 days ago
1 min read

Oak Wilt is a serious disease threatening oak trees across North America. While it is not yet widespread in our area, experts caution that the risk is rising in Eastern Ontario, and lake communities should remain alert.

Oak Wilt is caused by a fungus within oak trees. Infected trees can deteriorate quickly and may die within weeks or months, particularly red oaks.

Many shoreline oaks are at risk, and their loss would significantly impact our landscape and ecosystem. Oaks provide essential habitat, stabilize shorelines, offer shade, and hold long-term ecological value.

Be watchful for symptoms during the summer, including bronzed or brown leaves, rapid leaf drop, wilting, or sudden decline.

Protecting the natural beauty of Upper Rideau Lake is a shared responsibility. If you notice signs of Oak Wilt, please consult a certified arborist and inform the Association.

WHAT IS OAK WILT?

Oak Wilt is caused by a fungus that blocks water movement within oak trees. Once infected, trees—especially red oaks—can decline rapidly and may die within weeks or months.

HOW IT SPREADS

• Through underground root connections between neighbouring oaks

• Through sap-feeding beetles that carry fungal spores from infected trees to healthy ones

SYMPTOMS TO WATCH FOR (SUMMER)

• Bronzed or brown leaves

• Rapid leaf drop

• Wilting foliage

• Sudden overall decline in tree health

HOW YOU CAN HELP

• Avoid pruning oak trees from April to October

• Seal any accidental wounds with pruning paint

• Report any concerning symptoms