Trees, weeds and yards

Request services for city-owned trees. Learn more about pests, giant hogweed, and general yard care standards.

 On this page

  1. Public tree services
  2. Ash tree replacement
  3. Taking care of public trees
  4. Backyard tree planting program
  5. Spongy moths
  6. Giant hogweed
  7. Yard maintenance standards

Public tree services

Trees on public property (including parks, green spaces, trails and alongside roadways) are the city's responsibility to protect and maintain. 

We have a city tree bylaw that protects them from being cut down or harmed. The services below only apply to trees on public property.

Report damage

If a tree has been damaged by storm and poses an obstacle or risk to public safety, call us:

If you believe someone is harming a city tree, report it to municipal enforcement.

Request maintenance

Request maintenance such as trimming, pruning, or disease/pest diagnosis at 519-886-2310 (Monday to Friday, 8:30 a.m. to 4:30 p.m.).

Pruning is done by certified arborists who work to these standards:

  • the lowest branch over public sidewalks no less than 3 metres (8 feet)
  • the lowest branch over a roadway no less than 4 metres (14 feet)
  • trails and walkways must have 3 metres (10 feet) of vertical clearance and 30 centimetres (1 foot) beyond each edge of the trail

Request new tree

Call 519-886-2310 to request a new tree on public property.

Pest removal

We do not spray for insects because of the provincial pesticide ban. Visit the Ministry of Agriculture, Food and Rural Affairs website for more information

We do not remove insect nests within three metres (10 feet) of the ground unless they pose a safety issue. Bees, wasps and hornets generally do not cause a threat to human safety and play important roles in our environment as pollinators, predators, scavengers and prey.

Ash tree replacement

Emerald ash borer is a non-native insect that feeds under the bark of ash trees, disrupting the circulation of water and nutrients. Infested trees usually take up to five years to die.

We're committed to maintaining ash trees where possible and following a sustainable plan for tree management and removal.

Inspection, marking and removal

We inspect ash trees on city property on an annual basis, maintaining them whenever possible and replanting as quickly as possible after removals. Based on tree health, form and location, injections with TreeAzin insecticide are sometimes used to prolong the life of ash trees.

Residents will be notified of tree removals and replantings close to their property. Trees to be removed are marked with two red dots.

If a city ash tree appears unhealthy and isn't marked, call 519-886-2310 and we will inspect it.

Ash trees on private property

If you have ash trees on your property, there are some options to prolong their life span:

  • monitor closely for signs of decline, such as loss of leaves/dead branches in upper areas, thin crowns, bark splitting or exit holes
  • do not plant new ash trees, and remember that infected trees die quickly and become hazardous
  • insecticide injection may prolong the life of your tree long enough to wait for new treatment options
  • chemical treatment is most effective between June and August
  • tree removal is expensive, but may be necessary based on health of the ash tree. It is important to weigh your options and seek advice on the effectiveness of chemical treatments versus removal. 

Taking care of public trees


Young trees need lots of water to grow. We provide a water bag for spring-planted first year trees. This bag can be topped up at any time.

For subsequent years, a long slow soak is best so the water has time to move deep down into the soil and encourage deep rooting. Leave a hose to trickle slowly for at least 45 minutes or use about 20 gallons of water, poured slowly. Water 2 to 3 feet from the base of the trunk a couple times a month or as needed during drought.

When watering trees or lawns, follow the Region of Waterloo's watering schedule. Water from rain barrels or watering cans any day.

To help keep soils moist we use organic mulch. Keep mulch and other materials away from the trunk to avoid disease, shallow rooting, and rodent damage.


During the first year, a tree is spending a lot of energy growing roots. It is suggested to avoid fertilizer during the first year, especially those high in nitrogen. In future years a slow release organic fertilizer such as bone meal is recommended.

Digging around trees

Diagram of the protected root zoneIf you need to dig around a city tree's protected root zone (see diagram), follow these requirements:

  • all excavations using hand tools, air spades or trenchless techniques need to be carried out with great care to avoid damage to as many roots as possible
  • all roots over 25mm in diameter should be worked around and retained
  • any root cutting should be done with a sharp handsaw or secateurs (clean, straight cuts); size of the wound should be kept to a minimum 
  • mats of smaller roots (<25mm, including fibrous roots) should be retained
  • smaller roots can dry out and die when exposed, particularly in warm or windy conditions - they should be covered and protected with damp material until excavation is back filled
  • cutting of roots with a diameter > 25mm must be preapproved by the Manager of Forestry
  • when backfilling, do not tamp the soil too tightly, in order to allow oxygen and water to fill loose soil spaces
  • no more than 25 percent of the roots within the dripline for any tree should be cut or damaged
  • take extra precaution around sensitive and intermediate trees 

Use the following table to determine how sensitive a tree might be to root disturbance:

Species Tree Severance
American Elm Tolerant
Basswood Intermediate
Black walnut Sensitive
Bur Oak Tolerant
Butternut Sensitive
Green ash Tolerant
Hackberry Tolerant
Honeylocust Tolerant
Ironwood Sensitive
Mountain ash Tolerant
Red maple Tolerant
Red oak Tolerant
Silver maple Intermediate
Sugar maple Intermediate
White ash Tolerant
White oak


If you have questions about how to proceed around a city tree, call us at 519-886-2310 for advice.

Backyard tree planting program

Do you want to add a new tree to your backyard? We're working with Reep Green Solutions to plant trees in backyards at a reduced price.

The backyard tree planting program includes:

  • personalized property consultation
  • one or two native trees
  • delivery and full planting service
  • care and maintenance guide

Learn more and apply on Reep's website.

Spongy moths

The city is removes spongy moth caterpillars from city-owned trees. We encourage residents to remove them from trees on private property.

The best way to contain them is to:

  1. Wrap burlap around the trunk of the tree, a couple of feet above the ground.
  2. Collect the caterpillars as they come down the tree canopy during the day and get caught in the burlap.
  3. Check bands regularly and scrape caterpillars into a container with soapy water. Leave them for a few days and dispose in garbage.

View the video by Reep Green Solutions for the correct process to wrap trees.

We do not recommend using commercial sticky traps as they can kill insects, pollinators and birds.

The caterpillars have several native predators. These include mice, birds, chipmunks, skunks, raccoon, wasps and flies.

Spongy moth populations peak every 7 to 10 years. When moths are in the caterpillar stage they can be found in crevices in the bark of trees.

Thankfully infestations are not a yearly occurrence and healthy trees are able to recover even after significant defoliation.

Giant hogweed

Giant hogweed is an invasive perennial that's dangerous to people and pets. It must be removed from private property per our Lot Maintenance Bylaw. Find details in the section below.

On public property

Giant hogweed has been found across the city. In areas such as Bechtel Park this is an ongoing issue as there are a lot of seeds in the soil.

City staff monitor and destroy the plants in locations where it is known to grow.  It is important for the people and their pets to stay on official trails and avoid informal footpaths where it's more likely to be present.

Report a location

If you believe you have spotted giant hogweed on public property, follow these steps:

  1. Use this reference guide to confirm it is giant hogweed and not a similar looking plant.
  2. Confirm the location is in the City of Waterloo
  3. Take a picture of the plant and send it to along with location details.

If the suspected giant hogweed is outside Waterloo city limits, contact the Region of Waterloo for township locations or the City of Kitchener.

Yard maintenance standards

Contact our bylaw enforcement team to report yard maintenance issues.

Front yards

According to our Lot Maintenance Bylaw, you must keep your front lawn free of:

  • refuse, rubbish, garbage, brush, waste, litter and debris
  • injurious insects, termites, rodents and other pests
  • growth of grass or weeds in excess of six inches
  • noxious weeds (see below)
  • branches or bushes which overhang the sidewalk or road
  • dead, decayed or damaged trees
  • unused or unlicensed motor vehicles or trailers
  • stagnant water
  • machinery or parts
  • all furniture designed for indoor use

Noxious weeds

To comply with bylaws you must keep your yard free of noxious weeds such as:

Be careful when removing these weeds. 

Invasive plants

Residents planting invasive species in private gardens are an increasing concern, especially where they grow close to public green spaces. The Grow Me Instead guide provides tips on growing species that are best suited to growing in our environment.

View some of the common invasive plant species found within the Grand River watershed. You can report sightings and observations of invasive species through EDDMapS Ontario.

Encroachment on city land

Encroachment is the unauthorized use of public land for personal purposes, such as placing a shed, fence or other structure beyond your property line. This includes birdfeeders, play equipment, wood piles, pools, trailers, composters and gardens.

Our encroachment policy also regulates altering public land: you may not mow, prune or remove vegetation, plant trees or shrubs, or dump waste on public land.

Penalties for encroachment are up to $10,000. Our encroachment policy (PDF) sets out the process to remove encroachments and restore land at the expense of the person who encroached on it.


In Ontario you need a licence to use pesticides on your lawn. Visit the Ministry of Environment's website for more information.