The Online Gardener's Handbook 2010
Chapter 7: Lawns
Lawn Maintenance

Table of Contents

  1. Introduction
  2. Fertilize
  3. Water
  4. Mow
  5. Rake
  6. Overseed
  7. Grass Selection
  8. Learn More


As with all areas of your garden, the greatest protection against problems with your lawn is to ensure strong, healthy growth. A complete discussion of this topic is provided in OMAFRA factsheet 08-017: Lawn Maintenance.

Most lawns are made up of a blend of several turfgrass species. Kentucky bluegrass, tall fescues, perennial ryegrass and creeping bentgrass are the most common. All lawn grasses grown in Ontario are based on blends of these grasses, with Kentucky bluegrass as the major percentage of the blend.


Provide adequate, but not excessive, nitrogen-rich fertilizer. At least half of the fertilizer should be applied in the fall. This helps generate root growth, early greenup and moderate growth rates in the spring. Split the fall fertilizing into two applications: half from mid-August to mid-September and other half from late October to early November. The spring application is best delayed until early June. If it is applied in early spring, the high nitrogen content causes lush, succulent growth, which is more susceptible to disease. Do not fertilize in hot, dry weather because grass may burn or brown patch and other summer diseases may be encouraged. For low use lawns, fertilize only once a year in early fall.


Water your lawn thoroughly in the morning to encourage deep rooting. Do this only if the lawn appears dry. Excessive moisture, particularly in evening, favours disease.


Mow early in the day, as often as necessary, with a sharp mower. Dull cutting blades and evening mowing leave open wounds, allowing infection. Do not cut more than 1/4 to 1/3 off the top at any one mowing. Cutting more reduces the ability of grass to re-grow and makes it more vulnerable to injury. Remove excessive clippings to reduce thatch build-up.


Remove excess thatch by raking or de-thatching if it is greater than 2.5 cm deep. Core aeration will also help reduce thatch build up. The aerator or coring machine, available from most rental companies, has hollow steel tines placed 10 to 15 cm apart, which remove cores of soil and thatch 6 to 8 cm long. Aerating should be done when there is adequate soil moisture. If you do not wish to aerate the lawn yourself, a lawn care company can do the work for you.


Overseed problem areas with turftype perennial ryegrass. Its rapid germination and establishment rates will quickly fill in the bare spots or those areas where turf has died.

Grass Selection

One way to combat the damage caused by leaf-eating insects is to plant grasses that contain endophytes. Endophytes are fungi that grow inside the grass plant and make it taste bad. The lawn insects that find endophytes repellent are hairy chinch bugs, bluegrass billbugs and sod webworms. Some cultivars of perennial ryegrass, tall fescue and fine fescue contain endophytes.

Learn More

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