Brush up on a few winter gardening ideas to give your green thumb a workout all year long.
Jane Colclasure/P. Allen Smith
A raised garden bed is filled with cool-season vegetables, including (from front) broccoli, Swiss chard, onions, kale, purple cabbage and red lettuce.
Cultivate your love of gardening all year long by trying your hand at tending a winter garden. Your plot of ground might be a small winter vegetable garden, a container garden packed with winter annuals, or a few pots of indoor winter plants. Gardening in the winter can transform your indoor and outdoor spaces with living color.
Much of what you can do in outdoor winter gardens depends on where you live. If your address falls in Zones 7 to 10, you can tend a winter vegetable garden filled with frost-tolerant plants that will grow until spring. In these mild winter regions, you can also plant winter container gardens that survive chilly weather with ease. In colder zones, you can do some outdoor winter gardening, but the growing window will be shortened without providing some kind of frost protection for outdoor plants.
In all regions, the secret to winter gardening is knowing which plants survive the cold. Search out plants that are semi- or half-hardy for withstanding light frosts (29 to 32° F) and hardy ones for tolerating hard frosts (25 to 28° F). Semi-hardy vegetables adapted for winter gardening include Swiss chard, leaf lettuce, arugula, carrots, beets, rutabaga and radicchio. Flowers that fit this category include diascia, China aster, lobelia and petunia.
For hardy flowers, plant pansy, pinks, sweet alyssum, painted tongue or flowering stock. Hardy winter garden vegetables include radish, turnip, broccoli, English peas and leeks. A few plants withstand freezes that drive the thermometer to the low 20s and upper teens. These cold-weather all-stars are kale, spinach and collards, all of which grow well in a winter vegetable garden or winter container.
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.
Even in colder zones, you can raise hardy vegetables and flowers if you’re prepared to cover plants when necessary. You can use frost blankets, bed sheets, a plastic-covered tunnel or cold frame to extend your winter gardening season. You can also grow many salad greens indoors using containers and supplemental lighting.
With outdoor winter gardens, determine ahead of time how you’ll water plants. Depending on how severe the cold is in your region, you may or may not be able to haul a hose to your winter vegetable garden or containers. If you’ll be carrying water, position your garden, if possible, to limit water-toting duties.
Aim to get your winter garden crops established before frosts arrive. Actively growing, established plants withstand cold weather better, as do plants that have experienced the gradual downward shift of outdoor temperatures.
Indoors, focus winter gardening efforts on houseplants that flower during cool weather. Most of these beauties aren’t difficult to grow, and they add delightful color and possibly fragrance to indoor settings. Consider winter plants like moth orchid, with flowers that last for weeks, or cyclamen, with its artfully marbled foliage and butterfly-like blooms.
White or winter jasmine infuses a home with exquisite perfume, as do paperwhite narcissus bulbs, which are completely goof-proof. Even pots of rye or wheatgrass make a wonderful indoor plant that provides a pocket of greenery and a chance to practice some winter gardening.