Grow cold-hardy vegetables in winter
Grow cold-hardy vegetables in winter to get a serious head start on spring. From mache to spinach to peas, here are five vegetables that can survive temperatures as low as 10°F (-12°C) and can be seeded by late winter.
For the vegetable grower, winter can be a frustrating time of year with several weeks still to go before the official start of the growing season. If you’re craving fresh home-grown produce, good news: many vegetables can be sown by late winter to give a super-early start.
Many age-old farmers talk about “waiting for the light” before sowing seeds of cold-hardy vegetables in late winter. The daylight starts to increase quickly with each passing day by mid-February.
Peas can germinate at temperatures as low as 39 degrees Fahrenheit which makes them an excellent starting point. Growing peas for shoots is an easy way to get a fresh hit of flavor within just a few weeks. Pea shoots taste just like peas and are packed full of nutrients.
Pick a vigorous, tall-growing variety to give plenty of leafy growth. Start the seedlings off in a greenhouse or cold frame, sowing two to three seeds per pot or module cell. Once the seedlings have filled their modules they can be planted out to leave 8 inches between each clump. Cover the newly planted shoots with horticultural fleece to help them get going. Pick little and often by snipping off just above the second set of leaves.
Some salad leaves are incredibly cold hardy, including. mache (also known as lambs lettuce or corn salad), Oriental leaves such as mizuna and mustard, and the fleshy leaves of winter purslane (miner’s lettuce). When given sturdy protection from ice, snow and cold winds, I have often seen these little guys survive temperatures as low as 10°F.
You can sow seeds inside a greenhouse, a cold frame, or under row covers or cloches. Or, you can sow into small trays with grow lights indoors. Space plants at least 10 inches apart to give them plenty of room. Pick just a few leaves from each plant at a time to avoid exhausting the plant.
Cabbage is another one of the big hearty vegetables. And starting off cabbage this soon in the season has its advantages: slugs are thinner on the ground and you’ll enjoy a cut of vitamin-rich leaves by early summer—way ahead of spring-sown cabbages.
As with any early-sown vegetables, choose varieties suited to sowing in cooler weather. Sow into module trays then plant out once the young plants have established, usually within four to six weeks. Plant them 9 inches apart.
Spinach is the classic cold-hearty veggie and ready to sow under cover from late winter, as light levels start to improve from their midwinter low. Spinach is crammed full of vitamins and iron, making it a valuable crop for health as well as taste.
Sow directly into containers of potting soil or into modules (trays) or pots for planting out a few weeks later. Set three to four seeds per module for planting out 6 inches apart. When the plants are growing more vigorously you can pick a few leaves from each plant at a time, allowing replacement leaves to grow. In this way you’ll enjoy several harvests from each plant.
Green Onions (or Scallions)
Hardy varieties of green onions, also known as scallions, can be sown directly into fertile, well-drained soil. Sow seeds thinly in rows 6 inches apart. The seedlings shouldn’t need thinning out if they are sown thinly enough. You can also sow three seeds per module to plant out at 3in (7cm) apart in both directions.
Place covers over your green onions to help them along. Depending on your local climate and weather, the first stems will be ready by mid spring, when most gardeners will only just be starting to think about getting them underway.
In most cases you will need to offer your early risers some form of cold protection—particularly in snowy regions. The main priority is to raise the soil temperature high enough for successful germination while holding off the worst of frosts. Here are three types of setups (which each have pros and cons).
1. Cold frames block wind beautifully as long as they have a heavy lid that won’t cave in when loaded with ice, snow or heavy rain. A cold frame is basically a bottomless box with a transparent roof to let light and heat in. You could even use an old glass shower door. Be creative! See how to make a cold frame.
2. Reinforced tunnels (hoop houses) made from arches of wire fencing or concrete reinforcing wire, covered with plastic securely tucked in at the edges, also do a great job protecting hardy seedlings. Simple hoops covered with plastic will not do; the wet snows typical of late spring will smash such a tunnel flat, and gusty winds can do wretched things to slack plastic tunnels. But if you already have tomato cages made from concrete reinforcing wire, you can easily bend them out into arches and then cover them tightly with plastic. When weather turns very cold, I usually cover such frames with an old blanket to help them hold more warmth. See how to make a simple row cover tunnel.
3. Window frame toppers have become a favorite way to push the season because they offer the sturdiness of a cold frame with the convenience of tunnels. Old windows cleaned of paint work well. Add a coat of latex to seal in the old paint and re-caulk the panes before bringing them into the garden. To install them, it takes about ten minutes to set up a frame of staked boards and slip in a couple of windows. Ventilate these window-topped beds from the side, by leaving gaps in the frame, and/or from the top, by spacing the windows a finger’s width apart.
Protection Against Pests
It doesn’t take much to protect plants from hungry pests. In most cases starting seedlings under cover will avoid slug and mouse damage. Make it easier to spot and destroy slugs by picking off any dead or yellowed leaves and by keeping the ground between plants free of weeds, then check regularly after dark or lay beer traps to drown them. If mice become a problem under cover you may need to resort to a few strategically placed humane mousetraps - or talk nicely to the neighborhood cat!
Outside, birds such as pigeons and sparrows can attack young shoots of vegetables such as cabbage and peas. Don’t let them compromise your early start – set up netting covers if necessary to keep your crops safe.
With a little protection from the cold there’s no reason to delay sowing until spring. Sneak a head start and you’ll be harvesting fresh produce weeks in advance. Please share your own experiences of growing extra-early vegetables by leaving a comment below.
When you’re ready to start planning out your garden, use our online Almanac Garden Planner? Get a free 7-day trial for Mac or PC—and now iPad—so you can plan from your couch in the colder months and even bring out to the garden in spring.