Winter Vegetable Garden
Discover easy ways to keep your winter vegetable garden growing strong—and savor a long harvest.
Set your sights on a winter vegetable garden. Growing your own food and savoring those garden-fresh flavors is an amazing experience. In order to succeed with a winter vegetable garden, you need to understand a few basics of growing crops in the chilly season, as well as which vegetables to grow in winter.
Tending a winter vegetable garden is similar to a warm-weather growing experience—with a few key exceptions. First, once temperatures drop, many warm-weather pests and diseases disappear. Cool-season pests may appear, such as slugs and aphids, but the slower pace of cold-weather growing makes staying on top of problems a little easier.
In many regions, winter vegetable gardens don’t demand as much water, since winter rains arrive to help with irrigation chores. Also, plants don’t grow as quickly, so water needs diminish. Rely on soaker hoses and drip irrigation for the most efficient watering, delivering water directly to soil.
Another key in the winter vegetable garden is adding organic matter or fertilizer to soil prior to planting. It’s important to prep the winter vegetable garden in this manner because many soil microorganisms won’t be as active during the colder season. Reduced microbial activity affects how plants grow and take up nutrients. Amending soil ensures that ample nutrition is readily available to plant roots.
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
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.
To determine which vegetables to grow in winter, you’ll need to know your area’s USDA Hardiness Zone. That information tells you how low temperatures typically fall in an average winter. This low temperature represents a cut-off point for choosing which crops you can grow unprotected.
Hardy vegetables tolerate hard frosts (25 to 28° F). In other areas, you might need to provide frost protection on occasion throughout winter. Examples of hardy vegetables include English peas, kohlrabi, leeks, broccoli and Brussels sprouts. Radish, turnip and collards also fit into the hardy veggie category.
A trio of hardy vegetables can tolerate temperatures from the upper teens to low 20s. These cold-weather winners are kale, spinach and mustard greens. In regions where winters are mild, like the Pacific Northwest, Southeast and Southwest, hardy vegetables thrive outdoors all winter long.
Semi-hardy vegetables tolerate light frosts (29 to 32° F). These veggies include a host of healthy greens, including leaf lettuces, arugula, Asian greens, endive and Swiss chard. Beets, carrots, rutabaga, radicchio and savoy cabbage also fit into this category. These vegetables thrive outdoors all winter long in the mild-winter regions of the Pacific Northwest, Southeast and Southwest.
Winter vegetables need a solid start before winter arrives, because once cold, dark days settle in, plants won’t grow gangbusters, like they do in the summer months. The general rule of thumb for planting a winter vegetable garden in Zones 7 to 10 is to plant during October. In Zone 6, get plants in the ground in late September. Finesse the timing with resources from your local extension office.