If you’re new to gardening, you might not know that you can also plant a winter garden. Summer isn’t the only time that you can raise vegetables and grow your own food. With the right planning and a little work, you can harvest fresh vegetables ready for your holiday table.
Many vegetable plants love chilly weather and flourish in the cold. They even become sweeter, with a better-developed flavor. Depending on where you live, you can extend your growing season by choosing those plants that tolerate frosty temperatures. And if you’re able to make a few accommodations, you can even harvest all year round.
Planning Your Winter Garden
In order to make the most of any growing time, start planning your winter garden early. The window for growing in the wintertime is so narrow and the temperature fluctuations so extreme that you want to make sure you’re prepared well in advance.
For example, you’ll need to get your winter beds ready before the ground freezes, so you’ll need to know which plot of garden you’ll need to clear of summer growth first. Choose quick-maturing vegetables for summer so you can use the same plot for your winter garden. You may also decide to put in a cover crop before planting your winter garden. Will you have time have enough time after harvesting the summer tomatoes and grow a quick crop of clover to till under before fall?
The first thing you need to understand about winter planting is how the U.S. Department of Agriculture classifies weather and temperature with regards to growing plants. To determine which plants will work best for you, you should understand the following terms.
A frost occurs when nighttime temperatures drop below 32 degrees Fahrenheit, leaving a layer of ice on plant matter. Many plants are capable of surviving a frost.
A light freeze means that the temperatures have fallen between 29 and 32 degrees Fahrenheit. Tender, cold-sensitive plants cannot usually withstand these temperatures.
When temperatures dip to 25 to 28 degree Fahrenheit, it will kill most plants. Note that this means it will kill the plant above ground. That is called “die-off” or “die-back.” Most perennials rebound from die-off and regrow from the roots after temperatures rise in the spring. Annual plants, however, will die off completely with a light or moderate freeze.
When temperatures drop below 24 degrees Fahrenheit, heavy damage can occur to all but evergreen plants. While some perennials will survive and rebound in the spring, it’s possible they can become permanently damaged at these temperatures.
A hard freeze occurs when temperatures dip below 25 degrees for more than 4 hours at a time. Generally, this means that your perennials will definitely die back for the winter and your annuals will not recover.
You’ll see terms like “first frost date” and “last frost date” when planning your winter garden. First frost date is the day when you can first expect to see frost in the fall or winter. These dates are determined by averages over the previous years, and you’ll find them helpful for planning your winter garden. Since many seeds and seedlings are sensitive to frost, you want to ensure your cold-tolerant plants are well established before the first frost date.
Before planning your winter garden, find your hardiness zone. These are the designated areas determined by the USDA based on the lowest temperature averages in your region. Knowing this information can help you decide what to plant in your winter garden.
You'll find your hardiness zone by entering your zip code in at Garden.org. We highly recommend you use this handy tool rather than relying on the map. We recently discovered that because of our position on the coast, we were in a completely different zone than we originally thought, and this opened up an extra month for gardening activities.
The USDA maintains relationships with universities for assisting both home and commercial growers. You’ll find a great deal of information through your local extension office, including best plants for your winter garden and when to start them. You may also be interested in having them do a soil test on your garden. You can even take low-cost Master Gardener classes through the program. Find the extension office near you for these great resources.
Placing Your Winter Vegetable Garden
Make sure you place your winter garden where it will receive the most sun and protection from wind. Your garden site should receive plenty of sun during that time of the year. South-facing walls along buildings are excellent because they provide for the reflection of light and heat along with a barrier against the wind. Areas under trees, overhangs, and arbors retain heat well, too, as long as they get some sunlight during the day.
You can also try container gardening if you have room to bring your plants indoors during a freeze. Keeping containers near the patio or porch helps them stay warm, and it’s easy to throw frost covers over them quickly.
If these options aren’t available to you, you can use a few other techniques to grow your vegetables during the colder months.
Ways to Protect Your Winter Garden
Some vegetables will be fine if you leave them out in the cold, and some even end up sweeter after a bout in the snow. However, you can also nurture a few that might be a bit more sensitive by creating a warmer environment to extend the harvest.
Mulch can help protect your hardy winter garden vegetables from a hard freeze. Providing a layer of mulch can prevent damaging roots should temps dip lower than expected. It also helps retain moisture. One of the most damaging factors that can hit your winter garden is wildly fluctuating temperatures. Sometimes it’s not just the freeze that damages your plants, but the cycle of freezing and thawing that damages delicate plant tissues. Choose a biodegradable bark mulch, and you’ll also add nutrients to your garden soil for the long haul.
You can use glass or plastic cloches to protect winter plants from frost and freeze. The glass types are usually very quaint and attractive. You can also make them cheaply out of plastic from leftover milk or water jugs. The problem with cloches is that they’re usually pretty small and can only protect one plant at a time.
A frost blanket is another line of defense against dipping temperatures in your winter garden. You’ll find them in a range of thicknesses, so choose the one best rated for your hardiness zone. You can find blankets to protect plants from temperatures ranging from 28 to 24 degrees F. Thicker blankets will provide more protection from the cold but can also block out more sunlight. So, keep that in mind if you intend to use one for extended periods.
Although you can lay frost blankets directly on your plants, you may want to build frames using PVC to hold them up. That allows better ventilation and can create a pocket of warmer air around your winter garden plants. It also can make it easier to remove and let in more sunlight. And if you leave it in place, you can also cover your seedlings with a lighter bug screen or UV fabric to prevent summer scorching.
Anything that holds the frost blanket over the plants can do in a pinch. Use tomato cages, decorative fencing, or old shelving. Note that the edges of the frost blanket need to touch the ground completely to seal in the warmer air. Anchor them to the ground around the plants with rocks, lumber, or other heavy objects. If you’re planning to keep them in place throughout the winter, bury the edges in the ground around your garden.
Managed properly, a cold frame can extend your fall planting into a winter garden, while also helping you get an early start on spring. A cold frame is a sturdy box structure topped with a clear glass or acrylic door that allows in sunlight and traps heat.
You can purchase cold frames with light acrylic tops online or build your own. Reusing old windows or shower doors is one way to recycle materials and save money.
You can also create heat in a well-built cold frame. Adding extra compost about six inches below your soil generates heat while it continues to decompose. Some gardeners dig a hole about a foot deep inside their cold frame, add fresh manure and straw, and then cover it with soil. The decomposition of this hot pocket of fresh manure generates heat inside the frame. Be careful if you use this trick, however, since fresh manure can burn your plants. Make sure you provide the “hot pocket” plenty of room on all sides.
Cold frames can also be painted flat black on the sides to absorb more heat from the sun. Add damp hay as a mulch that will rot under the cold frame and generate warmth for your winter garden. Digging them into the ground by 8 to 10 inches provides your plants with the best protection from the cold. However, you can also use them as a portable solution and move them where needed. Add mulch around the sides for better insulation.
Row covers come in kits that include a frost blanket layer and easy to install hoops for covering rows of vegetable plants. You press the hoops into the ground along the row and cover them with the included sheet of fabric to protect your winter garden from a freeze. Having supports and the frost blanket in one kit is convenient. However, if your beds aren’t laid out in rows, this might not be the best solution.
This structure is just the granddaddy of all row covers -- hoop houses use the same structural premise as a row cover, except on a grand scale. They can even be big enough for you to stand up in and move around comfortably. Often called “polytunnels,” hoop houses provide more room than most greenhouses. Many feature steel framing, ventilation windows, and heavy-duty covers.
You can also make your own with PVC piping, heavy duty plastic, and a plan. The advantage to this DIY model is that these hoop houses are usually very light and you can move them yourself if necessary. You should be able to grow a wide range of edibles in a hoop house, with plenty of room to spare.
The term greenhouse often refers to a permanent structure similar to a small hut, with extra windows to let in light. It allows you to garden throughout the year. The upside of a greenhouse is that it is a permanent structure. It provides protection for winter vegetables as soon upon completion. You can add electrical service and even plumbing at a later date, which allows you to grow many vegetables that don't normally grow in a winter garden. The downside of a greenhouse is that it’s a permanent structure, which means you’re stuck with its location and the design you’ve chosen.
You can get also get greenhouse kits online. Some comprise sturdy metal frames and polycarbonate sides, while others are simply dressier versions of the hoop house, comprised of metal or plastic piping and a sheet plastic cover.
Choosing Vegetables for Your Winter Garden
Once you have an idea what your climate will be like and what sort of resources are available for protecting your winter garden, you can begin choosing vegetables. Although most experts recommend you grow what you know you’ll eat, there’s something to be said for trying something new. Our family just discovered how good beet greens were in a salad because the seeds came included with a set.
Find the cultivars that work best in your region by checking with your local extension office. They will provide information on which types do best in your region from hardiness to resistance to disease. The wide range of varieties and peculiarities of climate in the US are far too broad to cover in one article.
Plant in the fall
Plant these vegetables in the early fall for harvest in the winter or the following spring. Check the seed packets for “days to maturity” and compare it to the first frost date for your region. You may need to start seeds in mid to late summer and plant them in the fall once your beds are ready, depending on how long it takes them to develop. Some vegetables require a cold period in the ground to develop properly. You won’t be able to harvest them until the following spring or summer, but you’ll need to plant them in the fall, so they overwinter outdoors.
- Broad beans
- Brussels sprouts
- Collard Greens
- Green beans
- Green onions
- Mustard Greens
- Napa Cabbage
- Pak Choi
- Perennial Spinach
- Swiss chard
Tending Your Winter Garden
When planning a winter garden, remember that our ancestors -- even those as recently as 100 years ago -- didn’t have reliable refrigeration for storing food. While they made much use of canning and root cellars, they also weren’t hesitant to cultivate seasonal plants to eat through the cold months of the year. Those hardy plants are still available, and many brave gardeners face winter’s chill to harvest favorites like broccoli, cauliflower, and carrots.
With a little planning and preparation, your winter garden will become just as prolific as your summer garden. It may take some trial and error, and you may need to purchase or build hoop houses or cold frames. But the rewards will be worth it when you harvest and enjoy your first homegrown winter vegetable.
Have you tried gardening in the winter before? What are your favorite winter crops? Tell us what tricks you use to protect your plants from the cold in the comments below.