Ecological Lawn

1. Keep an open mind

For a long time, the picture of the perfect lawn has equated success and prestige. However, such a uniform, green lawn requires intensive upkeep that is often very expensive and not always environmentally friendly.

A healthy lawn can still play a decorative role, even if it isn’t flawless; and it will be less susceptible to diseases and insect infestations.

Learn to see your lawn as a natural environment and the presence of weeds and insects as being normal and acceptable. After all, these little imperfections won’t have any negative impacts, rather they will result in precious benefits for the environment!

2. Rake gently

In the spring, once the ground has thawed and dried out, gently rake your lawn to lift the blades of grass and remove debris. There’s no need to remove all of the yellow blades of grass: they’ll quickly decompose. Raking too vigorously may tear up healthy growth and be detrimental to the lawn’s growth.

Between mid-April and late May

3. Have the soil analyzed

To achieve a healthy lawn, first you need good soil.

Have your soil acidity analyzed by a garden centre employee or any other specialist in the field. An unsuitable pH (lower than 6 or greater than 7) reduces the strength of the sod, prevents nutrient uptake, and promotes the growth of weeds. Some species, such as hawkweed, burdock, bindweed, and sorrel, indicate acidic soil. 

Garden centre employees will guide you on the measures to take to maintain a soil pH between 6 and 7.

Between early May and mid-May or between mid-August and late August

4. Aerate as needed

If you cannot easily push a pencil approximately 10 cm into the lawn in several places, the soil is too compacted. The presence of some weeds, like plantain, are also a sign of compacted soil. You’ll need to aerate.

Mechanical aerators are available for rent and can be used to extract cores of soil when the ground is slightly moist. Avoid aerating when the ground is frozen or waterlogged.

Aeration provides:

  • better water and nutrient uptake;
  • increased oxygen levels in the soil;
  • better decomposition of organic matter, which fosters soil micro-organism activity.

Leave the cores of soil behind so that they can serve as top dressing. Break them up and distribute the soil evenly across the lawn using a leaf rake.

You can also enlist the services of a professional.

To be more effective, aeration should, ideally, be followed by top dressing and reseeding (see steps 5 and 6).

Between mid-May and late May or between mid-August and mid-September

5. Top dress

In the spring, after having aerated your lawn and before reseeding, spread compost, or in late summer, add soil high in organic matter. The soil must have a high compost content, in addition to topsoil, whose proportions vary depending on the type of soil.

Top dressing consists of adding a thin layer (1 cm or less) of soil directly on top of an established lawn.

This gradually improves soil quality, increases lawn density, and stimulates decomposition of organic material.


  • Apply top dressing with a shovel or by mechanical means.
  • Then, use a leaf rake to distribute the topsoil to the base of the blades of grass and to fill in the aeration holes if needed.

Be careful! Applying a layer of topsoil that is too thick (more than 1 cm) will suffocate the existing grass and have a negative impact on your lawn’s health.

Between mid-May and late May or between mid-August and mid-September

6. Reseed

Reseed your lawn and add compost to patches that are sparse or bare to prevent weeds from growing on them.

Use a grass mix (Kentucky bluegrass, rye, and fescue with endophytes). You’ll reap the benefits of each species, making your lawn more resistant to species-specific diseases. If you like, you can also add legumes, such as white clover. In fact, plants in this family have the ability to fix atmospheric nitrogen in the soil, thereby reducing your lawn’s fertilizer needs. Be careful! Some low-impact fertilizers that prevent dandelions also attack clover. Get the facts!

Did you know that there are specific plant species depending on the levels of sun exposure or the importance of treading? Before buying them, take note of the characteristics of the areas you need to seed. Why fight an uphill battle in difficult areas (heavy shade, steep slope, etc.)? Replace your lawn with other species of groundcover that are better adapted to the conditions. You’ll reduce the time spent mowing. 

Between mid-May and late May or between mid-August and mid-September

7. Mow high

Once spring has sprung, make sure you mow your lawn to 5 cm (2 in.) to stimulate lateral growth.

From then on, mow your lawn to 8 cm (3 in.). This will promote the development of deep roots and increase your lawn’s resistance to drought and heat. Long grass will minimize the growth of most weeds.

Mow your lawn regularly and never cut more than one-third of the height at a time to maintain your lawn’s vitality. Avoid mowing during periods of drought, when the grass is dormant and has stopped growing.

The last time you mow your lawn in the fall, cut to 5 cm (2 in.)

Sharpen your lawn mower’s blades at least once per year, to ensure a clean cut. Blades of grass mangled by dull lawn mower blades become dehydrated more quickly and are more vulnerable to diseases.

Don’t forget that one of the blades on new mowers is deliberately left unsharpened. When you purchase a new mower, make sure that all blades are sharpened!

8. Leave grass cuttings on the ground

Practise grasscycling by leaving your grass cuttings on the ground when you mow your lawn. Proper mowing will result in short clippings that are not visible, and are easily decomposed, providing nutrients to the soil.

If you don’t have a mulching blade, go over the lawn clippings with the mower a second time, if needed.

In addition to fulfilling, on average, 30% of your lawn’s nutrient needs, grasscycling enables you to:

  • reduce the time spent mowing and maintaining your lawn;
  • reduce the volume of organic materials in your brown bin and the odours generated by cut grass.

Dead leaves are also an excellent natural fertilizer. To accelerate their decomposition, shred them with your lawn mower.

9. Fertilize

Fertilizer gives grass the nutrients the soil is lacking. Packages of fertilizer feature three numbers (ex.: 8-2-2), which correspond to the percentage of the following three elements: nitrogen (N), phosphorus (P), and potassium (K).

Choose a slow-release fertilizer with a low phosphorus content (less than 3%). This type of fertilizer releases small quantities of nutrients over long periods of time rather than releasing everything at once. This slow, prolonged release enables plants to absorb the nutrients according to their needs, which reduces the potential risk of water pollution while preventing issues related to over-fertilizing, such as the presence of insects. A properly fertilized lawn is stronger and more resistant to problems, which minimizes the need to resort to pesticides.

Several small applications, at the right time and in the right amounts, are recommended. Follow the application instructions carefully.

To reduce your lawn’s fertilizer needs, adopt good practices: sow clover, spread compost, practice grasscycling, and shred dead leaves in fall. Refrain from applying fertilizer within 15 m of a watercourse and don’t spread fertilizer on hard surfaces.

Between early and late May or between mid-August and mid-September

10. Discourage and control invasive species

Make it a habit to regularly inspect your lawn and keep an open mind. A few weeds and insects are not a problem.


Pull weeds by hand while removing roots (use a weeding trowel or a narrow trowel). If possible, wait until after a rainy day; the soil will be much moister thus facilitating weeding. Fill holes with compost and seeds.

To prevent weeds from spreading, mow your lawn before or during the blooming period and seed sparse patches in the spring and late summer.

Dandelions flourish in soil that is lacking calcium and has excess potassium. To make up for a lack of calcium, you can add lime to your lawn.

As a last resort, you may need to use a low-impact pesticide.


The larvae of the common June beetle, European chafer, and Japanese beetle, commonly known as grubs, sometimes cause significant damage to lawns by feeding on grass roots. The affected areas turn yellow or brown and remain dry even after watering. They can be lifted like a carpet. 

Are skunks and other small mammals making holes in your lawn? Do groups of birds peck at it? These are signs of grubs. Check how many there are by lifting up a 30 cm2 patch of grass. There is a risk of infestation if you find more than five larvae under this patch of grass.

One way to get rid of grubs is to apply nematodes in the evening, when it is cloudy or raining and it isn’t too hot out, in August or September, when the larvae are young and vulnerable. Nematodes are parasitic microscopic worms that infect insects. Use the variety Heterorhabditis bacteriophora (HB), they are more effective and more concentrated. Keep your lawn moist for 10 days following the application. Above all, carefully follow the instructions when applying the nematodes to ensure the application is successful. Don’t hesitate to consult a professional.

Hairy chinch bugs

Hairy chinch bugs are very small (approximately 3.5 mm long). These insects perforate the leaves and stems of grassy plants to suck out the sap, which kills the blades of grass.

Lawns on sandy ground, in full sun and exposed to dry conditions are the most susceptible to chinch bug infestations.

The first signs of infestation usually appear between mid-July and mid-August, and are often visible near hedges, trees and flower beds in the form of irregularly shaped, yellow patches that increase in size. If the issue is not dealt with, the grass will die. Damaged grass remains rooted in the soil as, unlike grubs, hairy chinch bugs do not eat grass roots.

Use the following method to figure out if the damage to your lawn was caused by hairy chinch bugs and not by dryness.

  • Remove both ends of a large can (such as one used for coffee) and push it 5 cm (2 in.) into the lawn.
  • Fill the can with soapy water, adding water if the level drops.
  • Wait 5 to 10 minutes. The chinch bugs will float to the surface of the water.
  • Repeat on various patches of lawn, particularly around the edges. If you count 5 to 10 chinch bugs each time, the infestation is severe enough to damage your lawn.

Low-impact pesticides, such as insecticidal soap and pyrethrin can be used to get rid of hairy chinch bugs. Don’t hesitate to call upon the services of a specialist.

Next, seed the affected zones, ideally with resistant varieties of grass (endophytic fungi in particular).

Is your lawn infested with bugs? Start checking in May. A quick response is more effective.

11. Water responsibly

Lawns do not need much watering. Precipitation can meet 65 to 100% of their needs, depending on the season. The difference can be made up by watering while respecting municipal by-laws.

For lawns, perennials, hedges, trees, and shrubs

Watering using a spray gun or a sprinkler is permitted only on Sundays and Wednesdays, between 8 and 11 p.m. The use of a programmable system with a moisture sensor is permitted on Sundays and Wednesdays, between 5 and 7 a.m.

If you have planted a new lawn or are treating with nematodes, watering is permitted at all times for 15 consecutive days, upon presentation of proof of purchase.

In prolonged periods of drought, lawns become dormant and turn yellow to better resist stress. It is not dead and doesn’t need additional watering. It will bounce back after the rain.

For vegetable gardens and annuals 

Watering is permitted at all times using a spray gun, watering can, or programmable system with a moisture sensor. You should use only the small amount of water required to meet the needs of these plants. Do not allow water to run off into areas not targeted by the watering.

12. … and take pride in your sustainable lawn!

Obey the laws of nature by following these steps, accept your lawn’s diversity and be creative!

Don’t forget that transitioning to a sustainable lawn may not produce the expected results in the first year. Rest assured, your sustained efforts will be rewarded. Your environment and health will be better off!

For more information

Consult the Maintenance Guide for a Healthy Lawn (2.0 MB) (in French only). 

You may also contact an environment and sanitation inspector or the green patrol at 819-821-5905.