Ever-concerned about the environment and your health, Town of Mount Royal prohibits the application and use of synthetic pesticides. Environment-friendly alternatives exist: learn about them!

You can have a green and healthy lawn without pesticides

Toxic products like synthetic pesticides are detrimental to the environment. Helpful insects, wildlife, pets and even humans may be adversely affected.

To avoid contamination and limit the use of toxic chemicals, Town of Mount Royal has adopted By-law No. 1436, which prohibits the use of synthetic pesticides in the Town.

Certain exceptional situations may require using normally prohibited chemical products. In such cases, obtaining a permit beforehand is mandatory, failing which you could be subject to a fine between $100 and $4,000.

Live greener: look to alternative solutions!

Though synthetic pesticides are prohibited, many organic and environment-friend alternatives exist.

Some problems can be prevented simply by changing the way you garden or by physically removing the pest. For example, pulling weeds by hand is an effective and safe alternative to using a chemical weed-killer.

When other methods fail, there are a number of products you may use, though they must be authorized by the Town. Our Green Line can inform you about the types of product to favour to deal with any problems you face. These simple ingredients, which you can easily buy at your local hardware store or garden centre, can be used to treat your garden. Take advantage of this mine of information and try these products at home.


First, try to determine how many ants you are dealing with and where they are located. A few ants around your patio or the occasional ant inside your home are normal occurrences and pose no threat. More often than not, ants enter homes in the spring and summer in search of food and soon leave. To control this minor inconvenience, try placing small ant traps (5% Borax) around entry points to your home.

If you are finding many ants in your home, around exterior storage areas or in your lawn, garden or driveway, there may be a nest nearby. Don’t keep rotting wood, compost bins or refuse near your house because they can serve as a breeding ground for hungry ants. Also, store all food products in tightly sealed containers.

To exterminate the colony, try using bait with borax, a mineral that is toxic to ants when ingested. You can purchase premixed solutions or make your own. Here’s how:

  • Add 2 to 3 g of borax to 80 to 150 ml of water.
  • Mix in a sweet substance (honey, syrup or molasses, for example) to serve as bait.
  • Place the mixture in small aluminum plates and leave the plates in areas where ants are found. If children or pets have access to the areas, put the mixture in a sealed container with small holes so that only ants can reach the product.

To kill ants on contact, use silicon dioxide, which is sold as diatomaceous earth. Diatomaceous earth can also be used against cockroaches, earwigs, fleas, silverfish and centipedes/millipedes.

Snails and slugs

You can use copper barriers to prevent snails and slugs from entering your plant beds. Garden centers also sell a soap-based mixture that repels these harmful pests.

Baits with ferric phosphate are also highly effective. Ferric phosphate is toxic to snails and slugs but doesn’t harm animals or humans.

Small insects

Common liquid dish detergent is a multipurpose insect killer. The fatty acids in detergents target small insects such as spider mites, thrips and aphids. A homemade mixture of 30 to 60 ml of detergent in every 4 liters of water sprayed on affected areas will kill these insects on contact. Garden centres also sell premixed commercial insecticidal soaps.

Mineral oil (sold as horticultural oil) also controls pests such as mealy bugs and mites.


The problem may be poor-quality soil that’s more hospitable to weeds than to grasses. Fortunately, safe and smart alternatives to synthetic herbicides exist.

To control occasional weeds, you can treat your lawn with solutions made from acetic acid (highly concentrated vinegar), sodium chloride (a highly concentrated saline solution) or fatty acids. These solutions are available premixed and ready to use at garden centres. They are intended to be sprayed directly on the weeds, not on your grass. Corn gluten meal is a natural weed suppressant that prevents undesirable seeds from germinating. That said, the best way to eradicate weeds is to remove them manually (by hand or using tools) and to keep your lawn healthy.


You can prevent an infestation by placing barrier tape around the trunks of your fruit, forest and shade trees.

Btk (Bacillus thuringiensis subspecies kurstaki) is a biological insecticide that affects caterpillars. Moments after ingesting Btk, caterpillars stop feeding on plants and slowly die off. Btk is non-toxic for humans and animals.

White grubs

See our document: The fight against white grubs

White grubs are the larvae of scarab beetles; the most common species in our area are the Japanese beetle and the European chafer. They have a year-long life cycle that begins between late June and late July, when adult beetles lay their eggs in turf grass. Once the eggs hatch, the grubs feed on the grass’s roots, causing damage to your lawn. During the winter months, the grubs descend deep into the soil and wait until spring, when they resurface to feed on shallow roots. The larvae enter their pupa stage in May and emerge as adults in June.

Getting rid of white grubs is a multi-step process. As always, the best strategy is prevention.

  • Avoid lighting your yard at night and keep the mowing height for your lawn at 8 cm.
  • Avoid overwatering your lawn during the late spring and summer.
  • Incorporate white clover into your lawn. White clover is toxic to white grubs and stays green even during droughts.

Having a healthy lawn with deep roots is also important because it will be more resistant to white grubs. Good gardening practices such as aerating your soil, adding compost, fertilizing, reseeding and mowing high are all part of an effective prevention strategy.

To eradicate white grubs in your lawn, try nematodes. A biological method for controlling white grubs, nematodes are microscopic parasites that descend into the soil and feed on the grubs. It is crucial that they be applied between mid-August and mid-September, when the grubs are closest to the surface and at their most vulnerable. When applying nematodes, follow the directions closely for maximum effectiveness.