Remove spongy moths and giant hogweed
Learn how to manage spongy moth caterpillars and report or remove giant hogweed.
On this page:
Remove spongy moths
Spongy moth caterpillars eat leaves and can weaken trees. Residents should remove them from trees on private property.
What to know about outbreaks:
- natural predators include birds, mice, chipmunks, raccoons, wasps and flies
- outbreaks peak every 7 to 10 years
- most healthy trees recover after leaf loss
How to remove spongy moths
- Wrap burlap around the trunk about 60 cm (2 feet) above the ground.
- Check the burlap during the day for caterpillars.
- Scrape them into a container of soapy water, leave for a few days, then put in the garbage.
- Do not use sticky traps — they can harm birds and pollinators.
Watch the Reep Green Solutions video for instructions on how to wrap a tree.
Report or remove giant hogweed
Giant hogweed is a harmful invasive plant. Its sap can burn skin and harm pets. Stay on official trails in parks and trails where it grows, such as Bechtel Park.
Report giant hogweed on public property
Giant hogweed has been found across the city. We monitor and destroy plants where it is known to grow.
To report giant hogweed on public property:
- Confirm the plant using this reference guide.
- Confirm the location is in the City of Waterloo.
- Take a photo and email it with the location to environment@waterloo.ca.
If the plant is outside the City of Waterloo, contact the Region or Kitchener.
Remove giant hogweed on private property
Under the Lot Maintenance Bylaw property owners must remove giant hogweed, poison ivy and ragweed from their yards.
To remove giant hogweed safely:
- follow safe removal practices or hire a qualified contractor
- handle and dispose of plant material with care to avoid sap contact
Contact us
For questions about pests or invasive plants, call 519-886-2310 or email parkservices@waterloo.ca.