Series of posts on fall and winter vegetable gardens. We included lots of info on planting, structures, and winter garden care. Many of you were inspired to keep your summer gardens going longer or to plant seeds just for fall and winter harvesting. Again this fall there has been a lot of interest in extended-season gardening.
Rural Living Today‘s Fall and Winter Vegetable Gardens
Part 1: Intro to Fall and Winter Gardening
Part 2: Protective Materials and Structures
Part 3: Getting Ready for Fall and Winter
Part 4: Frost Protection
Find all of our extended season gardening links on one page here.
Growing Fresh Vegetables in Fall and Winter
Many of us grow vegetables during the summer growing season. But did you know that with a little extra TLC you can harvest fresh food throughout a chilly fall and winter?
Where do you live?
In areas with moderate winters, many plants can be grown year round out in the open garden. In fact, summer may be too hot for the cool-season greens and other veggies. You may be able to put in a fall crop of heat-loving plants like tomatoes, okra, peppers, and squash for harvest in the mild days of winter.
On the flip side, where winters are cold and frosts are inevitable, fall signals the end of life for those warm-season plants. But that doesn’t mean the fresh veggie season has to end!
With special care, we can extend the harvest of summer crops. And what’s more, many greens and other veggies can be grown through the fall and winter, providing fresh produce even on the snowiest of days.
Four keys to success:
- Selecting the right plants and varieties
- Starting with mature plants
- Planting in a sunny, accessible site
- Protecting plants from the elements
Which plants to grow
For the most part, the focus is on leafy greens and root vegetables. See our list of suggested plants below. Within each plant group, some varieties thrive better than others in frigid temps. Here are some general guidelines.
- Many root crops may be left in the ground, mulched well, and harvested as need throughout the winter.
- Hardy vegetables such as carrots, kale, leeks, and mâche may need nothing more than poly hoops.
- Less hardy vegetables and herbs may require a cold frame to continue providing fresh greens for several weeks or months. Perennial herbs (rosemary, sage, thyme) may remain green longer in this environment, delaying dormancy.
- Fruiting warm-season plants like beans, eggplant, peppers, squash, and tomatoes may continue to bear or ripen fruit in a heated greenhouse.
When selecting varieties, look for words such as “cold tolerant” and “cold hardy.” The resources listed at the end of this post indicate some preferred varieties for fall and winter gardening.
When to start seeds
All plants should reach maturity before cold weather sets in. Some will continue to grow in protective structures; others will be in a “holding pattern,” maintaining their freshness until harvest. Seeds should be planted well before the average date of first frost.
- In many Northern Hemisphere areas, ideal sowing dates fall between July and September.
- When time is short, select varieties that mature quickly.
- Some seeds may be sown outdoors during hot summer weather; others prefer to germinate at cooler temps and can be started under lights in a room that remains in the 70s F./low 20s C.
To determine the ideal last sowing date for a specific vegetable:
- If you don’t already know it, find the average date of first autumn frost in your area.
- Note the number of “days to maturity” listed on the seed packet or catalog info.
- Add an extra 10-14 days to account for fewer hours of daylight in late summer and fall (seed packet info is based on spring/summer planting).
- On a calendar, start with the average date of first frost in your area and count backward to reach the optimal planting date.
- Example: My packet of mesclun (mixed greens) seeds indicates the plants are ready to harvest in 28 days. I add on 14 days because I’m planting them in the late summer. Starting with our average first frost date of September 15, I count back 42 days and land at August 4, the ideal planting date. I may plant a little later than that, knowing that the seedlings will be nearly mature when the first frost hits. I can cover them with a protective material as that time approaches.
Where to plant
Accessibility is the first factor to consider, as winter veggies will do you no good if you can’t reach them! Many people like to site their structures near the house or a path that is well-used even in winter. Root crops buried under deep mulch can be placed anywhere, but plants growing above ground should be located where the sun will warm them on bright winter days. A south-facing slope is ideal. The sun’s rays will reach through clear and opaque row cover, polyethylene, plastic, and glass coverings.
Water should also be accessible nearby. Though your plants won’t need much water during the winter, they’ll need to be nurtured as they mature in late summer and early fall.
How to protect plants
Several types of materials and structures provide protection from frigid air and frost.
- Plastic or glass cloches (jars, jugs, bowls placed over individual plants for light frosts)
- Mulch (straw, leaves, pine needles)
- Row cover fabric (flat or hooped)
- Plastic or polyethylene hoops (film placed over rigid hoops)
- Cold frame (protective sides with clear glass or plastic lid)
- Greenhouse (unheated or heated)
Using two or more materials together will increase the protection. For instance, cover mulch with row cover fabric. Place a poly hoop over row cover. Put a cold frame or poly hoop inside a greenhouse.
The veggies and herbs in the following list can usually be grown or harvested during the fall and winter seasons. Whenever possible, select a quick-maturing variety. Also consider your growing structure and the height of each plant, selecting a more compact variety for a short cold frame.
- Bok Choi
- Brussels sprouts
- Leaf Lettuce/Mesclun
- Mâche/corn salad
- Pak Choi
- Radishes (especially Diakon type)
- Scallions/Green onions
Most of the plants listed above can be directly sown outdoors or started indoors. However, some prefer a cool germination period. If your daytime outdoor temperature is above 80 degrees F./ 26 degrees C., it’s wise to start the following seedlings indoors.
- Mâche/corn salad
Favorites of experienced winter gardeners
Niki Jabbour’s Top Ten*
- Winter lettuce
- Asian greens
Home Garden Seed Association’s Top Ten**
- Salad greens
- Swiss chard
- How to Make a Heat Mat for Seed Starting
- **“Sow Seeds for Fall Garden” from National Garden Bureau at GRIT Magazine
- “Cold Frame Gardening” at Kitchen Gardener Magazine
Protective Materials and Structures
In Part 1 of Growing Fresh Veggies in Fall and Winter, we talked about the basics. Here’s more information on the main types of frost protectors and links to some sources to get you started.
How they work: Protect individual plants from light frosts; raise temperature slightly
How to use them: Place over individual plants when frost is expected, remove when temps are above freezing. Usually placed in the evening and removed in the morning. Can also be used with early spring plant starts.
Sources: Clean glass jars and bowls; plastic jugs and bottles with bottoms removed; manufactured cloches
How they work: Insulate plants in ground from freezing temps; maintain moisture in soil
How to use them: Layer thickly on top of mature root and bulb crops.
Sources: Compost, straw, deciduous leaves, evergreen needles
Row cover fabrics
How they work: Insulate plants and soil from frost; raise temperature slightly; protect from insect and bird damage. Water and sunlight pass through them.
How to use them: Lay over plants (flat over small seedlings, loosely over tall plants); use over hoop frame. Since they “breathe” they may be used day and night—no need to remove when temps are warm. Can also be used during spring and summer seasons.
Poly low tunnels/hoops
How they work: Insulate plants and soil from frost; raise temperature; maintain humidity
How to use them: Install hoop supports and secure poly film over hoops; use drip irrigation on soil or lift cover to water plants. Leave ends open during cool weather, close ends during frigid weather. Poly tunnels may be used day and night—no need to remove when temps are warm.
Extend Your Growing Season by Barbara Pleasant at Mother Earth News
Use Low Tunnels to Grow Veggies in Winter: Quick Hoops by Eliot Coleman at Mother Earth News
How they work: Insulate plants and soil from frost; raise temperature; maintain humidity
How to use them: Construct or purchase cold frame with solid sides and clear glass or plastic cover that can be propped open for temperature and humidity control.
DIY: Can easily be made with wood, straw bales, other materials and a window or shower door cover.
Make a Cold Frame for Herbs (great cold frame info for veggies too) by Barbara Pleasant at The Herb Companion
Cold Frame Plans (wood) by Betsy Matheson Symanietz at Mother Earth News
A Cold Frame to Build (straw bales) by Paul Gardener at GRIT
Cold Frame Gardening at KitchenGardenerMagazine
Greenhouses, high tunnels
How they work: Sun shines through clear glass, plastic or polycarbonate walls, creating a warm and humid environment for plants. May be heated or unheated.
How to use them: Start seedlings, harden off seedlings started in warmer room, extend production of warm-season plants, overwinter hardy plants.
DIY: Planning and Building a Greenhouse from Maryland and West Virginia Cooperative Extensions
The Benefits of Building a High Tunnel by George Devault at GRIT
Getting Ready for Fall and Winter
In Part 1 of this series we talked about the basics of growing veggies in cool fall and cold winter temps. Part 2 was an overview of the materials and structures that protect plants from cold-weather damage. Today we’re moving toward the planting stage with some more steps to take.
Prepare your soil before planting
- If you’re using an existing garden bed for fall and winter plants, it’s a good idea to add some compost before planting. The summer growing season saps nutrients from the soil and may affect the texture of the soil as well. Compost will improve the texture and add some nutrients without overloading the soil with fertilizer or requiring decomposition.
- When using fresh topsoil or planting mix in a new bed or cold frame, amend as you would for a spring or summer planting season. This will vary according to the texture and nutrient content of the soil or mix.
- If you’d like to test your soil first, use a home kit, local test lab, or a mail-in service such as University of Massachusetts Soil Lab (our favorite–fast and reasonably priced).
- Wherever legumes (beans and peas) have grown the previous season, the soil is probably rich in nitrogen, as legume plants actually instill nitrogen in the soil. This is a good location to plant leafy greens.
Start seedlings indoors or out
- While local stores may not carry seeds in late summer, mail order seed companies usually maintain their ordering and shipping processes throughout the year.
- Some seeds are slow to germinate—or won’t sprout at all—when soil is hot. If your late summer brings heat and scorching sun, it might be easier to start those seeds indoors in a room that’s cooler than the outdoor temps. Greens and other seeds typically planted in spring fall into this category.
- Warmth-loving seeds can be directly sown even in a hot July and August.
- Short-season plants may be sown in September as long as the plants will be near maturity by the time cold weather sets in.
Plan protection strategy and get structures ready
In Part 2 of Growing Fresh Veggies in Fall and Winter we talked about several ways to protect plants from frost and cold. Using two or more together creates opportunity for many combinations as the temperature changes.
Here’s one example of a strategy for plants to be grown through the winter.
- Direct sow or transplant into garden bed during late summer.
- Leave in garden with row covers during light frosts.
- Add poly hoops for heavier frosts.
- Move to cold frame or greenhouse to withstand frigid winter temps.
Late summer and early fall are great times to decide how to protect your plants and gather, purchase, or build whatever you need. Then when a frost is in the forecast, you’ll be ready to cover those plants and keep them alive and happy through the coming months. See Part 2 for more info and resources.
Mulch root crops
- Before heavy frosts arrive, cover mature root crops like carrots and radishes with a thick layer of mulch such as straw, deciduous leaves, or compost.
- A layer of row cover cloth over the mulch adds a few more degrees of protection and may prevent mulch from blowing away in the wind.
- This is also a good way to winter over perennial herbs and vegetables that will sprout in spring.
- In many areas fall is the best time to plant garlic cloves for harvest the following summer. Garlic likes some time to establish roots and rest for a few months before a growth spurt in the spring. Mulch as for root crops to protect the garlic bulbs from frost damage and disruption from soil heaving during freeze/thaw cycles.
Lay out row cover
- Use row cover to protect plants from frost, birds, and insects.
- The fabric allows air, water, and light to penetrate.
- Row cover may be laid over or under drip irrigation tubes.
- Leave fabric slack to allow for plant growth.
- Secure at edges and between plants with staples, U-pins, or weights such as rocks or pieces of lumber.
Set up poly hoops
- Hoops may be put over row cover for extra insulation.
- Secure hoops and poly covers as needed to withstand wind.
- Leave ends of poly covering free to be opened on sunny days.
- Plan for accessibility for harvest by opening one or both sides of cover.
- Clothes pins or heavy clips can be used to attach poly covering to hoops.
Build a high tunnel or greenhouse
- Many style and material options are available. An Internet search for “build high tunnel” or “greenhouse plans” will result in lots of different ideas and schematics.
- If locating a structure away from garden, make sure water is easily accessed for watering plants until heavy frosts hit.
- A high tunnel or greenhouse normally used in summer may need to be winterized with additional material, doors, or window coverings.
- Inside a high tunnel or greenhouse, plants may be grown directly in the ground or in containers.
- For extra insulation over plants or around containers, row cover, poly hoops, and cold frames may be used inside high tunnels and greenhouses.
In Part 4 of Growing Fresh Veggies in Fall and Winter, we’ll tell you about our own plans and planting processes for our fall and winter garden.
In many areas, fall frosts are just around the corner.
In some, they have already made an appearance. Time to get those vegetable plants tucked in for the winter! If you’re just joining our discussion of fall and winter veggies, you might want to start with Growing Fresh Veggies in Fall and Winter Part 1–and take a few minutes to read Part 2 and Part 3 while you’re at it.
Once you’ve figured out how to protect your plants from the cold, get your system in place.
The next steps depend on your own plans, but here are some ideas.
- Put mulch over root vegetables. Several inches of straw or leaves works great. A layer of row cover or other porous sheeting over the mulch will prevent the material from blowing away while allowing sun and rain to warm and water the soil.
- Place row cover over garden plants for defense against light frosts. Lay it directly over the plants and anchor edges with pins, stones, or pieces of lumber. Or support the row cover with hoops or another type of framework. Clothespins, metal binder clips, and other types of clamps will keep the material secure but allow you to open the sides to harvest veggies.
- Erect hoops or low tunnels over planted beds and cover with plastic or polyethylene for protection from harder frosts. Again, clips and clamps are helpful for open-and-close weather protection and harvest access.
- Transplant existing plants and seedlings from your garden bed to a cold frame or greenhouse. This includes herbs and veggies left from summer planting as well as new salad greens started for fall and winter use.
Row cover drapes and hooped plastic can also extend the season for some tender plants that aren’t quite finished producing or ripening by fall. This includes melons and squashes as well as peppers and tomatoes.
Remember these tips
- You can quickly build an inexpensive cold frame with four bales of straw and a glass window.
- Most plants should be mature by the time heavy frosts arrive. However, the magic mâche (also known as corn salad) will grow in cold weather as long as it has germinated and gotten a good start in warm soil. There’s still time to start mâche seeds indoors and transplant them to a cold frame later.
Here’s an idea of what we’re trying out at our farm this fall.
We’re using our main raised bed, which has four sections divided by cross supports.
- In two sections, plastic-covered hoops will be put over mature herb plants and some fresh starts of salad greens.
- A third section of the raised bed, planted with carrots and radishes, will be mulched with straw and topped with row cover.
- The last section of the raised bed contains a fall crop of green peas. They’ll be covered with hooped row cover and then plastic until the harvest is over. Then we’ll turn under the pea vines and that area will go fallow for winter, waiting for our earliest spring plantings next year.
Some potted plants will be kept in our new small greenhouse. It’s unheated but has electricity if we choose to use it. We’ll keep an eye on things and see how things go this first year. We want some fresh veggies growing near the kitchen door for easy access, so we’ll use an old storm window and straw bales for a simple cold frame. We’ll plant a few types of salad greens and herbs there, easy to grab without trudging through the snow.