Weed Control

As outlined in the City of Leduc’s Integrated Pest Management Plan (IPM), we aim to use pest management strategies which are the least disruptive to the environment, as well as the most cost-effective.

Pesticides are used as little as possible

Herbicides used are applied in a target-specific manner as opposed to wide spread spraying. The only areas treated with herbicides are athletic fields and city facilities because weeds like dandelions can pose a safety risk to athletes using the fields. Areas surrounding city facilities are sprayed to maintain the city’s assets.

The only other spraying is for noxious weeds as required by the Alberta Weed Act. Any time pesticide application occurs there are warning signs to inform residents and park users. Signs are posted 24 hours prior to herbicide application and remain in place at least 48 hours after application.

We don't spray for dandelions

Since they're not listed by the Alberta Weed Act, dandelions are considered a non-regulated nuisance weed. Cultural and preventative practices like proper soil management, mowing, and adequate nutrient and watering programs are often enough to prevent the spread of dandelions.

The only areas treated with herbicides are athletic fields and city facilities because weeds like dandelions can pose a safety risk to athletes using the fields. Areas surrounding city facilities are sprayed to maintain the city’s assets.
The herbicide used by the city to control dandelions is called Par III (or a similar type of herbicide). Par III is able to selectively target broad leaf weeds while not harming other plants and turf. It is made up of 3 active ingredients: mecoprop, 2, 4-D and dicamba. All 3 of these substances have been approved by the Canadian Pest Management Regulatory Agency (PMRA) of Health Canada. PMRA has determined there is no evidence these substances are harmful to humans, animals and the environment when used responsibly in the manner they are intended for.

Preventing & Controlling Weeds

The best method of dealing with invasive plants is through prevention and quick response to new occurrences. These measures will help you maintain a healthy lawn and garden that can resist weeds:

  • Ensure there is 15 - 25cm of loam soil and or compost to establish a healthy lawn.
  • Aerate your lawn in the spring and fall and top-dress with loam to improve the soil surface.
  • Crowd out weeds by over-seeding your lawn.
  • Maintain your gardens with native plants suitable for plant hardiness Zone 3.
  • Hand pulling/digging is one of the best and most effective ways to remove weeds and the root system.
  • Mow weeds before they go to seed. This will stop the spread of the weed and will eventually eliminate the weed entirely.
  • Try out companion planting. This can often eliminate weeds because they don’t grow as effectively when they are close to certain plants.
  • Apply an organic fertilizer to help promote root growth, improve lawn colour and increase resistance to disease and weeds

As a last resort, consider spraying weeds with herbicides. If you do choose to use herbicides, use the most environmentally-friendly option possible and use spot treatments rather than blanket spraying.

Invasive Weed Control

Invasive plants are those which have been introduced, intentionally or unintentionally, from other countries or ecosystems and threaten Alberta’s ecosystems and biodiversity. They are able to reproduce and spread rapidly because they have no natural predators and are often well-adapted and aggressive so they out compete native species. Invasive species are even considered the second greatest threat to biodiversity worldwide.

There are many costs and impacts associated with invasive plants including:

  • Costs of prevention, control and mitigation
  • Disruption of natural ecosystems processes
  • Alteration of soil chemistry which prevents re-growth of native plants
  • Increased soil erosion
  • Poisoning of livestock and wildlife
  • Decreased habitat for native wildlife
  • Interference with forest regeneration
  • Allergic reactions

The Alberta Weed Act designates invasive/noxious weeds into 2 categories:

Prohibited Noxious: If these weed species are found on a person’s land they must be destroyed, meaning all growing parts need to be killed or the plant's reproductive mechanisms need to be rendered non-viable.

Noxious: If these weed species are found on a person’s property they are expected to control the weed, which means their growth or spread needs to be prevented.

The Alberta Weed Act does not consider clover or dandelions to be noxious weeds.

Click on the images below to learn about local weeds and how to treat them. Remember to bring all noxious weeds to the diseased wood pile. Use plastic bags to avoid spreading weeds to neighbouring communities. For a full list of noxious weeds, check out the Alberta Invasive Plant Identification Guide.