Once autumn's nip hits the nighttime air, it's time to winterize your lawn. The results of winterizing a lawn may not be visible until the spring, but these cold-weather steps lead to a healthier, greener, lusher lawn once the weather warms up again.

Choosing Winter Fertilizer

Every lawn benefits from a feeding of winter fertilizer made for grass. Still, this step is crucial if your lawn consists of cool-season grasses, which include fescue, bluegrass, and perennial rye grass. Because these turf varieties reach their prime in the cooler fall weather, they benefit the most from a good meal of winter fertilizer.

Winter lawn fertilizer is heavy on potassium, which strengthens the roots and helps the grass survive cold weather. A good winter lawn treatment keeps your turf strong and green through the fall and ready to perk up again once spring arrives.

If you have a warm-season lawn—Bermuda grass, zoysia, and St. Augustine are the most common—spring is the best season for deep feeding. These types of turf go dormant when frost hits, so they don't require a heavy winter fertilizer but do benefit from a light feed of regular lawn fertilizer with slow-release nitrogen to keep things green and healthy for as long as possible over the winter.

When to Apply Winter Fertilizer

The best time to winterize a lawn depends on your type of grass. If you live in an area without winter frost, your warm-season lawn may stay relatively green through winter. Go ahead and apply your slow-release nitrogen feeding in early autumn.

If you live in a mild winter area that does receive some frost, your warm-season lawn probably goes brown and dormant. In that scenario, do not apply fertilizer later than September 1.

For cool-season grass, it's best to winterize a lawn with two separate feedings: one application of winter lawn fertilizer in late summer/early fall and the second application during late fall or whenever the leaves reach peak color in your area. But if you want to keep your lawn care simple, apply the winter lawn feed once in late November or early December.

General Winter Lawn Care

There are a few other ways to winterize a lawn that will pay off come spring.

• Aerating your grass lets water and nutrients reach the roots quickly and easily and prevents the soil from becoming too hard and compacted. You can aerate a small lawn with aerating "shoes" or a manual push aerator. However, larger stretches of grass call for using larger push or gas-powered lawn aerators.
• If you have a warm-season lawn that goes dormant during the winter and you want to keep things green, fall is the time to overseed with annual rye grass. This quick-sprouting, fast-growing annual grass adds color to your winter lawn and then dies down with next year's heat.
• Overseeding is helpful for cool-season lawns as well because once those grass seeds germinate in the spring, they will crowd out competing weed seeds. Do your cool-season overseeding in the early to late fall.
• Fall is also a great time to reseed any bare or patchy spots of grass.
• You'll also need to keep up with weeding during the fall and through the winter. While some weeds go dormant in cold weather, their seeds are usually waiting to germinate in the spring. Pull established weeds by hand, and apply pre-emergent herbicide to prevent spring weeds.
• Whether or not you need to water your lawn in the winter depends on where you live. If you're in a warm winter area, your grass still needs to be watered, but you can cut back to once or twice per week, depending on the temperature, and turn the sprinklers off during rainy spells. Cold-winter gardeners should turn off the sprinkler system by the end of October and flush out the hose and sprinkler system to prevent freeze damage.

Mowing the Lawn in Winter

While you may still be mowing your lawn in winter if you live in a very mild climate, you'll certainly do it much less than in the spring and summer. Generally, you can cut back to half the frequency of your summer mowing schedule. And if you live in an area with rugged winters, you can cross mowing off your list of winter lawn treatments altogether—but not until the first hard frost.

Cutting your lawn in cold winter climates is a balancing act; once fall sets in, you should raise your mower's blades to a half-inch above your summer mowing height. For the last mowing of the season, however, lower the blades to a half-inch below the summer mowing height. This encourages root growth but removes grass blades likely to become damaged or diseased during the coldest months.

You might be tempted to leave fallen leaves on the lawn over winter, but whole leaves will smother your grass and provide shelter for fungi spores, insects, and other diseases. Either rake away fallen leaves, or for the best solution, mow over them with a leaf mulcher attachment that shreds leaves into small fragments. This leaf mulch adds a bit of protection and nutrients to your turf without doing damage.

Winterizing a Lawn Mower

If you want your lawn mower to start right up in the spring, you need to take a few easy steps to winterize it before putting it away for the season.

• Winterizing your gas-powered lawn mower begins with emptying the fuel tank. If there's only a little bit of gas left, let it run until it's empty after your last winter mowing session. If you have a full tank, drain or siphon out the gas. If you use a gas preservative, you can store it until spring. If not, use it in your snow blower or other gas-powered winter tool.
• Disconnect the fuel lines to empty them as well, and then rev up your mower one more time to burn off any trace of remaining fuel.
• Now it's time to clean your lawn mower. Remove the blade assembly and sharpen it—dull mower blades rip the grass and encourage disease. Apply a very light coating of oil before reinstalling the blades.
• Clean the bottom of the mower thoroughly, scraping away grass, mud, grease, and grunge. Wipe down all surfaces of the mower, and oil the wheels if necessary.
• Replace the spark plug and the air filter, and then change the mower engine's oil.

If you have a battery-powered lawn mower, the procedure is fairly simple. Remove the battery and fully charge it before storing it for the winter in a cool, dry spot, then follow the same cleaning process as with a gas-powered motor.

Lawn Mower Storage Tips

Once you've finished winterizing your lawn mower, it's time to store it for the season. Doing so protects it from rust, moisture, and general wear and tear. Finding storage for a lawn mower is sometimes tricky, however.

The easiest solution for push mower storage is your garage. If you have the space, you can tuck the mower into a corner of the garage and cover it with a tarp to keep insects and dust to a minimum. Or create extra space for lawn mower storage with a pull-down, lift-up shelf.

If your garage is large enough, you might also be able to use it for riding lawn mower storage. If not, a small side or backyard shed—either purchased or DIY—serves well as a winter home for your riding lawn mower.

If the only mower storage spot is outside, protect it with a fitted cover or tarp that covers the mower completely. Use bungee cords, stakes, or heavy rocks to fasten the cover in place securely.

While winter lawn care might not be as much fun as gardening in the spring, taking the time to do it right dramatically increases your odds of having a lush, green, healthy lawn once warm weather returns.