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How to Garden Outdoors in Winter and Grow Fresh Vegetables

These are our best tips for winter gardening

rows of green savoy cabbages with frost outdoors in winter garden

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Growing and harvesting your own vegetables and herbs is one of the best things about warm summer months. But, cold weather doesn't mean the growing season is over. With some basic knowledge and equipment, you can grow fresh veggies in winter, overwinter crops, and get a head start on spring.

Here's everything you need to know to grow vegetables in the winter.

What Is Winter Gardening?

As temperatures drop in fall, our summer gardens start winding down. Although heat-loving vegetables like tomatoes, peppers, and eggplants can't survive cold temperatures, plenty of cold-season crops can withstand late-fall frosts or survive outdoors until spring.

Others crops, especially lettuces and other greens, can be grown outdoors under protective cover or in an unheated greenhouse even in winter. You can also get a jump on the earliest spring crops by overwintering plants or winter sowing.

Know Your Hardiness Zone

The first step in planning a winter garden is to know your USDA hardiness zone. This designation will enable you to know the plants that can survive in your region at different times of the year. Each state can have several hardiness zones, so be sure to consult the USDA hardiness map to be sure you know the hardiness zone for your specific area. Note that climate change might mean that your area has become warm enough for some plants that couldn't be grown there previously.

Check Your First and Last Frost Dates

Once you've determined your hardiness zone, you'll want to check the first and last frost dates for your zone. This information will help you plant the right plants at the right time, which is key for season extension and winter gardening. It's important to know that these dates are estimates based on historical data, so always check your local weather forecast before planting.

Once you know your first frost date in the fall, you'll know which plants in your garden will be damaged by frost and should be harvested and which can survive outdoors with or without protection. Knowing your average last frost date in the spring can help you know when to plant cool-crop seeds indoors or outdoors and when to plant seedlings outdoors. Seed packets often indicate when to start seeds or sow seeds outdoors in relation to first and last frost dates.

How to Protect Vegetables In Winter

Growing vegetables in winter requires some extra protection in all but the warmest regions. Season extension methods like low tunnels or hoops, cold frames, cloches, unheated greenhouses, and even simple mulching can protect vegetables and ensure a winter or early spring harvest. Here are some of the best ways to protect your vegetable garden in winter.

Using Low Tunnels or Polytunnels

low tunnel hoops in garden covered with sheer white row cover

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Covering plants with some kind of protective material is one of the best protections against frost and freezing temperatures. This can be as simple as a layer of floating row cover, or Reemay (a polyester garden material) placed over a bed before your first frost date in the fall.

Using plastic hoops, sometimes called a low tunnel or a polytunnel if coated in plastic, ensures that mature plants have adequate space and won't be damaged by the covering. In cool climates, you'll want to double up on floating row cover to protect from extreme frost. In very cold climates, cover hoops with plastic sheeting to create a polytunnel, which can increase temperatures by as much as 30 degrees Fahrenheit.

Tip

Be sure to fasten or weigh down the row cover or plastic well to keep cold drafts from coming in to ensure your plants are protected.

Using Cold Frames

winter gardening cold frame made of wood and glass with winter vegetable starts inside

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A cold frame is a low, portable structure with a transparent lid that can be placed over a garden bed to create a warmer microclimate and protect plants from the cold. Cold frames can also be stationary so that plants can be seeded directly inside the cold frame. They can be constructed from old windows or plexiglass and straw bales or wood, or you can purchase ready-made cold frames that resemble small greenhouses.

On sunny days with temperatures above 40 degrees Fahrenheit, it's important to open your cold frame a few inches to avoid overheating the plants. Just be sure to close it back up again as temperatures cool later in the day.

Using Cloches

long plastic cloches over winter vegetable crops in raised bed garden outdoors in the sun

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A cloche is a clear cover that can be placed over a single plant or an entire garden bed to protect plants from the cold. A cloche can be made from plastic or glass; individual plants can be protected using a cloche made from upcycled plastic bottles or milk jugs. A cloche can also look like a one-piece mini greenhouse or polytunnel. Cloches are especially useful for protecting individual plants from a hard frost in late fall or early spring.

Using Greenhouses

clear plastic greenhouse in backyard covered with snow

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If you have the space and the budget, an unheated greenhouse can be an excellent winter gardening solution. Greenhouses can be made from glass or plastic built into a wood or metal frame. You can also purchase or build a structure called a hoop house or high tunnel that covers an entire garden or garden bed. To help minimize heat loss in your greenhouse, add thermal mass by placing water jugs inside. They'll absorb heat from the sun during the day and release it at night, keeping temperatures from dropping too low inside.

10 Vegetables to Grow in Winter

Plenty of cool-season vegetables and herbs can be planted in late summer or fall and overwintered until early spring. Others can survive into winter using season extension techniques and will taste sweeter when they're harvested in spring: as temperatures drop, vegetables like carrots, beets, and hardy greens convert their starches into sugar to protect them from frost. Leafy greens grow quickly enough that they can be sown and harvested outdoors in winter if they're protected. Here are some of the best vegetables to grow in winter.

Beets

Plant beets six to eight weeks before your last frost date in the fall and overwinter them under mulch or plastic row cover to harvest in spring. You can also grow beets for their greens rather than their edible roots. Sow every two weeks in a greenhouse, cold frame, or plastic-covered low tunnel for baby salad greens.

beets growing

The Spruce / K. Dave

Arugula

Zesty arugula is a quick-turnaround crop that thrives in cool spring or fall weather. Sow arugula seeds six weeks before your first frost date in a cold frame. Before frost hits, protect the plants with a cloche or use hoops with floating row covers or plastic. You can also sow arugula in a greenhouse. Sow every two weeks for continuous harvests through winter.

arugula plant

The Spruce / K. Dave

Kale

Start sowing this hardy green in early fall and harvest through to your first frost date. Use floating row covers or a cold frame to protect kale plants from hard frosts and heavy snow. With protection, kale plants can survive through to spring.

kale growing in a garden

The Spruce / Debbie Wolfe 

Herbs

Hardy perennial herbs like rosemary, sage, thyme, and lavender can withstand winter temperatures and regrow in spring with no intervention in all but the coldest USDA hardiness zones. If you'd like to harvest through winter, cover plants with row covers or plastic sheeting or move container plants into an unheated greenhouse before your last frost date. Soft herbs like parsley seeded in warm weather can be protected with row covers, a low tunnel, or a cold frame in cold weather and survive winter. Other soft herbs like chives planted in containers can be brought indoors or put in a greenhouse for winter protection.

closeup of rosemary

The Spruce / Randi Rhoades

Carrots

Sow carrots in late summer to allow them time to size up, as they won't grow much after cold weather hits. Leave some good-sized carrots in the ground to overwinter, covering the plants with several inches of salt hay or straw to insulate them from the cold. Harvest as needed throughout winter or wait until early spring to dig up your crop.

harvested carrots

The Spruce / K. Dave

Cabbage

To overwinter cabbage, sow seeds of especially cold-tolerant varieties in late summer. Depending on your growing zone, you can leave plants as they are or protect them with floating row covers or plastic sheeting when frost hits. You can also sow cabbage in a cold frame or greenhouse to use as baby greens for salads or cooking throughout winter.

cabbage growing in the garden

The Spruce / Autumn Wood

Garlic

Plant garlic cloves in the mid to late fall before the ground freezes. Shoots will emerge in late winter to early spring and continue growing until the garlic heads are mature in midsummer. Garlic greens can be harvested as green garlic or spring garlic and cooked fresh. Otherwise, allow the garlic heads to size up and harvest in midsummer.

hardneck garlic

The Spruce / K. Dave

Spinach

Plant cold-tolerant spinach varieties like 'Bloomsdale' about six weeks before your first frost date so that plants can become established. Use floating row covers or plastic sheeting over low hoops to protect plants if you'd like to harvest in winter. You can also leave spinach plants unprotected, letting the leaves die back, and they will regrow in early spring. Spinach can also be sown in a cold frame or greenhouse to be harvested in winter as a baby salad green. Plant every two weeks for successive harvests.

spinach growing in the garden

The Spruce / Kara Riley

Lettuce

Quick-growing, cold-tolerant lettuce is one of the best ways to grow vegetables in winter. Sow cold-hardy head lettuce varieties like 'North Pole' or 'Lollo Rosso' two to three months before your first frost date if you plan to cover them with row covers or plastic or six weeks before your last frost date in a greenhouse or cold frame. Harvest as needed through winter. You can also sow leaf lettuce for a baby salad mix in a greenhouse or cold frame six weeks before your last frost date, then every two weeks after that for successive harvests.

closeup of lettuce greens

The Spruce / Kara Riley 

Swiss Chard

Plant Swiss chard in late summer or early fall, then overwinter mature plants under row covers or plastic to harvest in December or beyond in areas with mild winters. Sow Swiss chard seed six weeks before your last frost date, then every two weeks after that in a greenhouse or under plastic-covered hoops to harvest colorful young or baby greens for cooking and salads.

growing swiss chard

The Spruce / Heidi Kolsky

Preparing for Spring Gardening

Once you've established your winter garden, it's time to start thinking about spring. Season extension works both ways: in addition to growing crops from fall into winter, it allows you to start your spring planting earlier.

Sow cool-weather crops six to eight weeks before your region's last frost date in a greenhouse for transplanting outdoors once the weather warms up, or get a jump on direct sowing under a polytunnel, row covers, or cold frame. The mature plants you protected over winter will wake up as the days get warmer and longer, giving you another early harvest to enjoy as the growing season gets going.