Growing Vegetables Outdoors in Winter
by Mary Jasch
This winter, when you’re planning your vegetable garden or potager and thinking about what to grow for fall and possibly even beyond – READ this first!
At Four Season Farm in coastal Harborside, Maine, Barbara Damrosch and husband Eliot Coleman, farmers, garden writers/authors, grow just about everything an epicure could want – all year round without heat. In summer, 35 crops grace their farm stand and, in winter, wholesalers reap the fresh, harvest bounty.
Winter? Outdoors? No heat in Maine, you ask? Sure!
They grow a smorgasbord of greens including spinach, mache, claytonia, arugula, lettuce, chard, beet greens, Asian greens; fresh dug root crops like carrots, leeks, scallions, baby turnips, radishes; and conventional storage crops such as winter squash, celery root, storage beets, potatoes…
The beauty of it is that you can grow them, too, right through winter in your own backyard.
Damrosch and Coleman grow outdoor crops into November. Then, in the very coldest months, January and February, they turn to unheated greenhouses. If you don’t have an unheated greenhouse in your backyard, listen up.
You can grow spinach and carrots in a cold frame, but harvest the carrots when they start to regrow, Damrosch advises. Carrots resume growth and start to go to seed when it gets to be about a 10-hour day (February in Maine, end of January/early February for NJ/southern NY). They don’t taste so good then.
Super hardy veggies: mache, spinach and claytonia.
Create a Climate
Four Season Farm creates the desired climate for their winter crops three ways: cold frames, unheated greenhouses and row cover fabric. Being at the 45th parallel with the same light levels as southern France and Genoa, Italy, they’re looking for a Mediterranean climate.
“All you’re really doing with a cold frame or greenhouse is creating a Mediterranean climate by removing the wind factor and allowing for more solar gain,” says Damrosch. “You can grow lots of salad crops and root crops in cold weather just in cold frames. The first time you try it on a 0° day, things might look pretty beat up, but if you wait until they thaw – even on a cloudy day they’ll thaw – they’re quite harvestable and perky.
“Many crops taste better and sweeter in winter. The spinach ‘Space’ is so sweet you won’t believe it,” she adds. Almost anything sweetens up in the cold – arugula is milder in the cold, parsnips and carrots get incredibly sweet. They’re our most popular crop. People call them candy carrots because after a few frosts they sweeten up.”
The most important thing when using a cold frame is to vent it every morning. Sun increases the temperature and cooks your greens. Be worried about over-heating, not under-heating. Prop the cold frame open and let the hot air out every day, unless it’s a real cloudy day at 15° in February, March or April. If it’s cloudy and you have to go out and you’re not sure what the weather will be, vent it.
Damrosch and Coleman started using greenhouses to avoid shoveling snow off their many cold frames. Now they use them inside a greenhouse as a second layer of protection. It also makes a better climate.
“In our cold frame it would be New Jersey weather, but if you put that cold frame inside an unheated greenhouse it would be Georgia weather,” Damrosch says. Just think of the climate you can create in DIG IT! Territory!
Out in the Field
The farm does not grow kale in a cold frame because, once cut, it does not regrow very well in winter. Instead, they leave it outdoors and cut from it through December. Brussel sprouts ditto. They also do very well with spinach grown outside; they just brush away the snow. And curly leaf parsley is a little hardier than flat-leafed.
When the couple went commercial with winter produce, they cut expenses by using floating row cover fabric (Reemay – a brand of white spun-bonded polyester fiber invented for filters) that lets light and moisture in but keeps frost and bugs out. Use it to protect tender crops – such as tomatoes or peas – against frost. A layer over crops inside a greenhouse has the same effect as a cold frame.
Damrosch and Coleman don’t usually bother with pest protection because their philosophy is “if you grow healthy plants and give them the soil they need and the conditions they need, they resist pests.” They do put Reemay over brassicas for root maggot and over potatoes for Colorado striped potato beetle. When plants are no longer vulnerable, they remove the cover.
Or, in the case of potato beetles, they wait to watch their numbers. Some years they’re prevalent, but last summer there were none in sight. “It goes to show that although the bugs are there, they’re not going to eat a healthy plant. The potatoes were getting exactly what they wanted,” says Damrosch. The summer’s straw mulch lessens predation, too. Just as in the rest of the animal world where predators prey on weaker animals in a herd, so do garden bugs prey on weak plants.
“Similarly if we eat right, get enough exercise and all those good things, we’re apt to stay very healthy, repel cold germs. It’s all very logical out there,” she adds. “People like to have an enemy. We’re being sold things that put fear into our pocket books. ‘Oh. My garden’s going to get all these things, I better spray.’ They put you at war – for their profit really. They get us on the wrong mind set.”
The pair farm 1.5 acres out of 40 very intensively. They can earn $80,000 an acre with the way they grow, soil fertility, choice of crops… “We pay a lot of close attention to everything,” says Damrosch of Coleman’s efforts to create a 19% organic topsoil from almost nothing. They don’t have raised beds – just trodden paths between beds they never step in to keep them fluffy. “It’s so much easier that way. You don’t need raised beds. In sandy soil they dry out very fast.”
Their formula: 30-inch x 100-foot beds with one-foot paths in-between. Thirty-inch beds are perfect for reachability and wider beds can cause back strain while reaching to harvest or weed. They are also easily stepped across from path to path. If crops are well-groomed and weeded, one foot paths are all you need.
“Maybe in a big garden you’ll have a two or three-foot central path but between those beds it’s only a foot,” she adds. “If it’s in a greenhouse, it’s expensive real estate. You want to make the most of every single inch.” Crops like spinach are planted six rows to the bed; carrots- 12; head lettuce - three.
Occasionally they heat certain greenhouses: one with a washing and packing area and, one for starting seedlings in spring, and one to start tomatoes for an early market. A wood boiler does the job with a propane back-up.
Favorite tomatoes: Striped German and Brandywine, but sometimes uses similar Burpee Brandy Boy for market; paste: Amish Paste heirloom; Big Beef for farm productivity.
Barbara Damrosch and Eliot Coleman write books and do TV shows about gardening and farming. “Also we’re communicators and researchers and try to move projects along in ways other people can imitate and build on. That’s a major part of our mission as well as simply farming for a living,” she explains.
Barbara Damrosch wants gardeners to know: “Get into the mindset of eating with the seasons. There’s so much to gain by this. People often think of this as a limiting thing but to me luxury isn’t being able to go into a supermarket and make any recipe you want. You can get all the ingredients into your basket on any day of the year, but to me the joy is to have each thing at its peak of goodness.
“I’d much rather wait for our Charentais melons to come in the fall or the first tomatoes or the first raspberries. Enjoy that so ecstatically throughout its season and then wait till that season gets to roll around again because each season has its great things. Summer arugula can be really harsh so wait until fall arugula comes in, but meanwhile you’re eating tomatoes or Swiss chard or something else that’s doing great at that particular moment.”
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published January 20, 2010