How to prepare your lawn for the winter

Our lawns bring a lot to our lives. They offer rest and relaxation. Kids love them, spend time growing up on them. They’re places where we gather with friends to celebrate. From a municipal perspective, they’re invaluable for managing storm water.

And what’s better than the scent of fresh-cut grass on a summer morning?

The trouble is, lawns can also take a lot from us if they’re not properly cared for. Much of that care can happen in the fall, as nights begin to consistently dip below freezing and grass growth slows. “A focus on plant health will always contribute to a kind of equilibrium,” says Dan Tavenier, NAIT landscape gardener. “That takes know-how and sensitivity.”

To help you reach a state of balance with your lawn, Tavenier recommends a few fixes for happier, healthier grass and roots that will require less chemicals and water, and give back more of the time you’d rather spend enjoying it throughout the summer.

Don’t water

Put away the hose. Unlike trees and shrubs, your lawn needs to go into the winter dry. This will prevent ice from smothering roots and, by slowing growth, helps grass acclimatize to winter.

Bag the last clippings

“Nature is the master recycler, second to none,” says Tavenier. Leaving behind your mulched grass returns valuable nitrogen to the soil – during the growing season. Once temperatures drop and the microbes that decompose things go dormant, those clippings will just get raked up in spring. Bag your last cut, Tavenier recommends, and compost it.

Also, don’t cut too short. Blades of grass contain stored energy that’s used by the roots over winter (they do not go dormant). Leave your grass at about two inches (five centimetres) tall.


To avoid stimulating growth, wait to fertilize until grass has stopped visibly growing. This should happen once daytime temperatures drop to 5 to 7 C and the nights dip below zero.

Mind your formulation. Many fall fertilizers are high in phosphorus – the middle of the three nutrient numbers that responsible for root development and health. Since Edmonton-area soils are already phosphorus rich, much of what you add will run off into the water table. “We don’t want to contribute to the pollution cycle,” says Tavenier.

Use a synthetic growing-season fertilizer and go light: about half a pound to 1,000 square feet (225 grams to 90 square metres). Organic fertilizers won’t work at this time of year. They need microbes to break them down and this won’t happen until the warmer days of spring.


Impressed by past results, Tavenier top-dresses every fall after he aerates. He spreads dry compost to a thickness of ¼ to ½ inch (0.6 to 1.25 centimetres). “When you rake it out it should be invisible.” With successive seasonal applications, top-dressing also improves grading, which prevents pooling and ice buildup that suffocates roots.


Most people aerate in the spring but Tavenier feels this is a job best done in fall. In addition to ensuring a 10 per cent aerobic (as opposed to anaerobic, or without oxygen) environment that roots require to thrive, aeration also helps your lawn absorb more of the spring melt and allows the ground to warm faster. Both will give grass a head start.

Over seed

A thicker lawn will decrease moisture loss, discourage weeds and improve the appearance and underfoot feel of your lawn. To avoid unwanted seed germination, which shouldn’t happen until spring, spread after freeze-up.


Follow these steps and rest easy with the knowledge that a balance has been struck. “You’ll get much better regrowth in the spring,” says Tavenier, “much better green-up.” And you’ll have to do less next year to keep it that way.

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