Winterizing Your Garden
Button up the garden before the deep freeze of winter arrives, and you’ll be on your way to a gorgeous season next year.
Get your landscape ready for the big chill by winterizing your garden. Tackling winter prep chores outdoors before temperatures tumble too far is a great way to squeeze in a little exercise and get a jump on next year’s garden. Everything you do toward winterizing your garden in fall helps smooth the way for a healthy, beautiful growing season next year.
Winter-hardy plants prepare for cold weather through a process called hardening off. This gradual change from lively growth to dormancy occurs in response to environmental signals, like changing temperature and day length. Even though plants enter dormancy, there are things you can do to help ensure they survive whatever winter brings. That’s where winterizing your garden comes in.
In chill-prone areas, the winterizing process actually begins in late summer to early autumn by withholding fertilizer. Growing plants lean as chilly weather arrives. This helps prevent them from initiating excessive new growth that won’t have adequate time to harden off before winter. Growth that doesn’t harden off winds up zapped by cold and can make plants vulnerable to other problems.
Before frost arrives, it’s important to water landscape plants well if rain has been scarce. Well-hydrated plants aren’t stressed, which means they’re healthier. Healthier plants survive winter better.
One aspect of winterizing your garden is adding a mulch layer around plants to help insulate soil and protect plants from frost heave. Use a loose, non-compacting material for mulch, like chopped autumn leaves, shredded bark, pine straw, chopped cornstalks or straw.
Before mulching, take a few minutes to clean up any plant debris, especially beneath disease-prone plants like roses. Old stems and leaves that remain in place through winter can provide hiding places for diseases and pests. Gathering debris helps give problem critters the boot.
Applying mulch is a key part of winterizing strawberries. Wait to add mulch to these plants until days are reliably in the 20-degree range or, in a mild-winter region, when soil temperature drops to 40° F for three consecutive days. Winterizing rose bushes requires a mound of soil over plant crowns before you add mulch. Allow the soil mound to freeze before mulching over it.
Winterizing a lawn mostly involves applying a special fertilizer, usually called a winterizer fertilizer, to lawns comprised of cool-season grasses, like Kentucky bluegrass, fescue or perennial ryegrass. Correctly timing the fertilizer application is critical. Get fertilizer on grass sometime in October or November. Discover the precise timing for your area from your local extension office.
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.
Winterizing your garden also involves rounding up plant covers for winter frost protection. Gather frost blankets, old sheets or cloth tablecloths and have them at the ready as temperatures start to fall. Use frost blankets to cover crops in a winter vegetable garden, to protect winter container gardens and to help tender plants survive a cold snap.
Don’t forget to winterize your water garden. The most important thing is not to let your pump freeze. Check with your landscape installer or a local garden center that specializes in water gardens to learn if you can allow water to run all winter long in your region.