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Healthy Shorelines for Healthy Lakes


Cottage with lawns

In North America, lawns now account for more than 8 million hectares of land use. Often chemical or organic fertilizers are applied to these lawns, and it is not uncommon for a typical manicured lawn to have between five and 10 times the concentrations of chemical fertilizers and pesticides as same sized areas in an agricultural setting. One of the main problems with overuse of chemical or organic fertilizers on shoreline properties, especially lawns, is that over 55 per cent of precipitation runs off lawns. On a shoreline property, the runoff goes directly to the adjacent water body, where it can upset the natural ecosystem.

Where lawns can’t be eliminated they can be placed farther back from the shore and natural lawn care methods can be used.


In 2009, Ontario’s Cosmetic Pesticides Ban came into effect, prohibiting the use of pesticides for aesthetic purposes. More than 250 pesticide products are banned for sale, and over 95 pesticide ingredients are banned for cosmetic uses. For more information about the ban and alternatives to pesticides, visit the Ministry of the Environment website. Thankfully, lower-risk pesticides, biopesticides and pesticide alternatives do exist.

Natural Lawn Care

A positive “green” action you can take for your lake and wildlife is to not use banned pesticides. Think of your shoreline as a small ecosystem where all the living organisms exist in balance. When we introduce pesticides we alter this balance. Pesticides often harm organisms other than those targeted as well as the surrounding environment, having serious negative effects. For instance:

•    Fish and aquatic animals are exposed to pesticides by absorbing them through their skin or through their gills during respiration, by ingesting pesticide-contaminated water or by eating pesticide-contaminated prey. This can lead to death, reproductive failure, tumours, lesions and deformities.
•    Pesticide runoff can harm natural algae grazing animals and increase the risk of algal blooms.
•    By eliminating certain insect or weed populations with chemicals you also affect those species that depend on them for food. Butterfly populations dwindle when their food sources disappear through herbicide use. Many birds, frogs, toads, bats and other animals depend on a good supply of insects to remain healthy.

The best defence against pests and diseases is to have a healthy lawn. Since more and more people are becoming aware of the negative impacts pesticides and fertilizers have on wildlife and humans, alternative natural methods of lawn care are being developed. Try these gardening practices:

•    Leave your lawn approximately 10 centimetres high to encourage the growth of stronger and deeper roots 
•    Leave grass clippings on the lawn where they will decompose and nourish the grass rather than wash into the water
•    Do not overwater as fungus and disease often prosper in these conditions

Control of Garden Pests

Garden Beds:
•    Remove insects with pressure sprayers of air or water or with pheromone traps, baits or lures
•    Consider planting insect deterrents and attractant plants in other areas of the garden. For deterrents, try garlic oil with insecticidal soap, baking soda or cinnamon.
•    Prevent weeds from growing using physical barriers (such as mulch) around plants
•    Remove weeds by hand

•    Use natural weed killers (such as corn gluten), which can feed turf grass and help eliminate weeds 
•    Prevent further weed growth after removal by covering the weeded area with a blend of topsoil and organic matter and grass seeds; this natural mixture will also help the soil regain a healthy composition

For more information on controlling garden pests naturally, visit WildAboutGardening.org

Man watching ducks in the water

Retiring a Lawn

Transforming your lawn to a more natural state will help protect both your lake and groundwater.  In areas close to shorelines, turf grass is not a good choice of ground cover. Turf grass has a short root system and does not bind to the soil as well as many native grasses; this can cause erosion along the shoreline. Turf grass along a shoreline also permits much more runoff and pollutants to pass over it toward the surface water. Remember that organic plant foods, manures and compost can also leach undesirable amounts of nitrogen and phosphorus into the water. By retiring areas of your lawn that are not actively being used and establishing a buffer, you will reduce maintenance and protect your shoreline from erosion. Leaving a naturalized buffer along the shoreline will also discourage Canada geese from enjoying your garden.

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