How to Grow Outdoor Veggies All Winter Long
Want to enjoy garden-fresh veggies throughout the winter? Monica Mansfield explains that, with a few steps, gardeners can protect their crops from the elements and reap the benefits during the coldest months.
Usually by the end of summer, gardeners are ready for a break from garden chores. Winter is a time to rest our bodies and plan next year’s garden. However, the fruits and vegetables from the grocery store taste like disappointment, and by January or February, I’m craving garden-fresh produce again. Luckily, if we put in a little extra work later in the summer, it is possible to enjoy goodies from our gardens all winter long.
Crops to Grow Year Round
In general, cool-weather crops can be grown to harvest throughout the winter. Ideal cold-weather crops include arugula, Brussel sprouts, broccoli, parsnips, spinach, kale, swiss chard, lettuce, carrots, beets, and scallions.
It’s also important to choose varieties that are cold-tolerant when planning your year-round garden. There are many varieties of lettuce, for example. Some do well in warmer weather, such as Ermosa, while others do better in cooler weather, like Red Salad Bowl.
The key is for them to be full grown by the time cold weather hits and then protect them from the elements. They won’t grow in the winter, but they can stay in the ground so you can harvest them when you’re ready to eat them.
This means that the time to plant your winter garden is late summer, so your plants are mature when the frost hits. The timing will vary depending on your zone. You’ll need to know your first frost date and then count backwards.
Let’s take broccoli as an example. Depending on the variety, it can mature anywhere from 50-85 days. Your seed packet will tell you the days until harvest. If you have an 85-day variety, you’ll want to direct sow it into the garden 85 days before your first frost. Once the frost arrives, you’ll cover your crop with a row cover to protect it until you are ready to harvest it for dinner.
It’s also important to note when you grow year-round, you are not giving your soil time to rest and replenish itself. Year-round gardening makes it imperative to add soil amendments to your garden so it doesn’t lack nutrients and give you a poor harvest. Compost is full of nutrients and an ideal amendment for every garden. Blood meal will add nitrogen, bone meal will add phosphorus, and lime will add calcium while also reducing pH in acidic soil.
Row covers are probably the easiest and simplest way to extend your season. Sometimes referred to as frost cloths or shade cloths, they are a lightweight, semi-transparent fabric usually made out of spun-bonded polypropylene or polyester. They come in different sizes and weights.
The lightest covers are usually used as insect barriers and don’t generally protect from frost. They let about 95 percent of light through and barely weigh anything.
Lightweight covers are a little heavier at about a half ounce per square yard. They lock in heat and moisture, so they are useful for starting seedlings in the spring. Plus, they will do a great job protecting your seedlings from insects, birds, and rabbits. They will increase the temperature by about 4°F and let about 85 percent of sunlight through to your plants.
Medium-weight row covers get a little heavier at 1-1.25 ounces per square yard and can be used to protect your garden from light frosts. They will increase the temperature by about 6°F and let about 70 percent of the light through. This isn’t enough light for plants to grow, so this type of row cover is best used in the winter months when plants aren’t actively growing.
Heavyweight row covers are the heaviest option and weigh 1.5-2 ounces per square yard. They will protect plants to 24°F and work well for protecting plants in the cold winter months. These will only let up to 50 percent of light transmission through to plants, so this type should not be used when plants are actively growing.
When you are using the lightest insect barriers and lightweight row covers to protect seedlings during the actively growing months, you can lay the row covers directly on top of the plants without causing any harm. However, during the cold winter months, when you’ll be using medium-weight and heavyweight row covers, leaving the fabric directly on the plants can damage the foliage.
You can easily build hoops out of PVC pipe to support the row covers. These hoops are easy to move around the garden as your layout changes each year. Pound a one-foot piece of rebar into the ground and then slide a ½-inch PVC pipe over the top of it to secure the ends of the hoop. Then use clothespins or other clamps to hold the fabric in place on the hoops. You can use rocks, bricks, or long boards to secure the row cover to the ground.
Read also: Cold Weather and Hydroponic Gardens
You can use these portable mini-hoop tunnels to extend your season in the spring. They will trap heat, warm the soil and give your plants frost protection. This way you can start spring crops a few weeks early. This works well for radishes, spinach, lettuce, arugula, carrots, beets, and peas. These same crops can be planted in mid to late summer for a fall garden, and these tunnels will extend the length of your fall gardening season.
When using these hoop tunnels in the winter, be sure to add a thick layer of mulch to protect your plants even further. You can also double up your protection by putting a hoop tunnel over a cold frame or inside of a greenhouse.
Cold frames are essentially mini greenhouses within your garden. Just like the hoop tunnels, they capture heat and protect plants from the elements. They are a bottomless box with a glass window or other clear material on top. They can be constructed of wood, cinder blocks, or even straw bales. You can build them to be temporary and moveable or set them in the ground as a permanent structure.
Temporary cold frames may not be well insulated enough for greens, however, with a thick layer of mulch they are perfect for root crops. Cold frames that are permanently set in the ground are better insulated and can grow your tender greens. You can also build your cold frame inside of a greenhouse for even more warmth and protection for year-round growing.
Read also: Extending The Growing Season
It’s important to be diligent about venting your cold frame. Heat can build up inside of the cold frame rather quickly and if you don’t let cooler air in, your plants could suffer. You’ll probably need to vent the cold frame daily in spring and fall, leave it open in the summer, and only vent it on mild days in winter. As a general rule, vent your cold frame during the day as long as it is warmer than 40°F, and then close the lid before it gets too cool in the evening.
You’ll need to check the plants in your cold frame daily. If the soil dries out, give them some water. Brush any snow or leaves off the top of the cold frame. Check for pests that may have found solace in the warm environment. Harvest your crop in the afternoons because your plants may be frozen in the mornings.
Gardening year round is possible. With a little extra work and the right techniques, you can eat delicious garden-fresh food all winter long and save yourself from the disappointment of store-bought veggies.