How to Winterize Your Lawn
Learn what to do to prepare your lawn for winter. Taking the right steps in fall prepares your grass for quick spring greening.
Fertilizing the Lawn
Apply fertilizer with a spreader.
Image courtesy of Ben Rollins.
Keep your turf in tip-top shape by preparing it properly for winter. This process, known as winterizing the lawn, involves simple steps that don’t require lots of time or money. When you winterize a lawn, you’re paving the way for lush, healthy spring turf.
The first step in winterizing a lawn is knowing what type of grass you have. Warm-season turf includes Bermuda, centipede, St. Augustine and zoysia. Cool-season turf usually contains fescue, Kentucky bluegrass or perennial ryegrass. Both warm- and cool-season grasses benefit from specific actions in fall to prepare them for winter.
Cool-season grasses grow most strongly in fall. Many lawn care experts recommend that if you choose to fertilize your cool-season lawn only once each year that you should do so in fall. The lawn fertilizer typically available in fall is called winterizer fertilizer. In most locations, you should aim to apply winterizer fertilizer in October or November. Check with your local extension service or garden center to time it right for your region.
The reason that fall fertilizing is so effective is because plants respond to external triggers in fall to start the process of preparing for winter. These triggers are things like daylength and temperature changes. As days shorten and air becomes cool, plants—including turf grass—respond by slowing growth and shifting food reserves from leaves to roots. Although air temperature continues to fall, plant roots remain active in soil. This is true of many different kinds of plants, including grass.
Shifting excess nutrients to roots is the secret to plants’ return each spring. Those stored food reserves fuel the spring wake-up. The same is true of your lawn. By fertilizing grass in fall, you’re feeding the active roots and giving them even more nutrients to store for winter.
When spring arrives with longer days and warmer air, grass blades sense the seasonal change and respond by kicking into growth gear, drawing upon those food reserves. Grass that is fed in fall greens up quickly in spring, growing thick and lush. A thick lawn crowds out weeds.
When winterizing a lawn, fertilizing is most critical for cool-season grasses. Treat warm-season lawns differently. In regions where late fall brings freezes, warm-season turf grass typically goes dormant in winter. In these areas, do not fertilize warm-season grasses after September 1, or you risk fueling new growth that will be damaged by freezes. This type of damage makes roots more susceptible to stress and damage.
Mistake No. 1: Planting Too Late
Making late additions to the landscape can result in devastating losses next spring, especially in areas where the ground freezes. Perennials are the most susceptible to late planting, as alternating freezing and thawing of soil literally shoves plants out of soil, exposing crowns. Shrubs and trees can go into the ground later, but for best winter survival rates, you should have all plants in place by six weeks before soil typically freezes.
Mistake No. 2: Pruning Shrubs
Pruning causes plants to produce new growth, which is tender and highly vulnerable to freezing temperatures. Wait to prune shrubs, including butterfly bush and caryopteris, until spring, when all danger of frost has passed. At that point you can remove any winter killed branches. In future years, aim to get pruning done by late August, so plants have time to harden off before freezes arrive.
Mistake No. 3: Planting the Wrong Varieties
Fall lettuce crops can linger well into December in mild winter areas. Plant cold-tolerant varieties to ensure the longest harvest period. Good choices for fall planting include ‘Four Seasons’ lettuce (shown), ‘Arctic King’ and ‘North Pole.’ To overwinter lettuce in regions with cold winters, plant ‘Winter Marvel’ or ‘Brune d’Hiver.’ In mild winter areas, sow seeds of ‘Four Seasons’ or any oakleaf type.
Mistake No. 4: Not Watering New Trees
Trees that you plant in fall need consistent watering as they enter their first winter. If winter brings frozen soil without snow, give your tree a drink during any times of above-freezing temperatures. One hose-less way to ferry water to a tree is with a water bag in a cart.
Mistake No. 5: Failing to Deadhead Self-Sowers
Plants that self-sow aggressively in the landscape can be beautiful in bloom, but a gardener’s nightmare if allowed to go to seed. Clip seedheads on plants that tend to self-sow heavily in your garden. Good candidates include joe-pye weed, goldenrod, boltonia and black-eyed susans.
Mistake No. 6: Skipping Mulch
A winter mulch can be a gardener’s best friend, especially around new additions to the landscape. That extra mulch layer can help prevent frost heave around new plants that may not have an extensive root system to help keep them anchored in soil as it freezes and thaws. Put a 2-inch-thick layer around the base of plants to insulate roots.
Mistake No. 7: Spraying for Weeds
Be sure to read the label of your favorite weed killer. For common chemicals like Round-Up, 50°F is usually the lowest temperature where the product remains effective at killing weeds. Many plants essentially stop growing as soil temperatures fall into the 50-degree range, so at that point spraying is a waste of time and money. The answer is to spray early in the fall season, while plants are actively growing and air temps are still in the ideal 60-degree range.
Mistake No. 8: No Pre-Snow Clean-Up
In snowy winter climates, aim to clean up the garden before early snowfalls arrive. Doing this helps to reduce winter resting places for pests and diseases that go into hiding once snow flies. It’s also easier on you—no frozen fingers.
Mistake No. 9: Not Destroying Veggie Crops
It’s vital to destroy spent vegetable crops, especially those that hosted problem pests, like Mexican bean beetles. Don’t toss these plants into a compost pile unless you know it heats enough to destroy pests and eggs. It’s safer to dispose of infested plants and fallen leaves in bags you put at the curb for garbage pick up.
Mistake No. 10: Failing to Use Frost Blankets
If you have a garden that’s actively producing when frost threatens, there’s no excuse for not investing in some season extending equipment to keep the fresh flavors—and nutrition—coming into your kitchen. This kit costs under $25 and comes with built-in hoops and the ability to extend up to 18 feet.
Mistake No. 11: Letting Grass Grow Too Long
In snowy regions, grass that goes into winter without being mowed is more prone to develop snow mold. Try to give grass one last cut before winter snows arrive. Also, once the ground freezes, stay off the lawn. Frozen grass is more prone to breaking as you walk on it, which can damage individual grass crowns.
Mistake No. 12: Not Wrapping Vulnerable Shrubs
Take time to wrap shrubs and small trees with a winter coat of burlap for protection against cold temps. Plants at risk include those with borderline hardiness and evergreens prone to winter burn. Spray evergreens with an anti-transpirant before wrapping in burlap. Before adding the burlap, protect trunks against chewing rodents by tossing mouse bait that’s enclosed in a protective container near the base of the plant.
Mistake No. 13: Failing to Protect Trunks
As food sources become scarce, rabbits, mice and voles can make quick work of bark on unprotected trees and shrubs. Use tree guards around young tree trunks, and surround shrubs with hardware mesh. You can also try to attract raptors like owls and hawks, which prey on these mammals, by erecting artificial perch poles.
In mild winter regions, warm-season grass stays green through winter. In these areas, you do want to fertilize the lawn in early autumn. Apply a fertilizer with a slow-release nitrogen source at modest rates to fuel long-term steady grass growth—which crowds out winter weeds.
With all lawn fertilization, don’t just do it mindlessly. If you already have a lawn that’s healthy and thick, and if you’re not sure when the last time you fertilized was or if you even need to fertilize, take a soil test. That’s the most definitive way to apply the right amount and type of fertilizer.