While the rest of us are gladly shoving our rakes, hoes and wheelbarrows into the garden shed with a sigh of worn-out relief, an altogether different breed of farmer is starting up their proverbial production engines and shifting into high gear. It’s September and they’ve only just gotten started. They are the off-season growers, composed of two parts mad scientist, one part “we will defy any odds” and a heavy seasoning of “I have to grow something at all times.” These are the people you want to know if the food system goes down. They can pull a sweeter-than-your-momma carrot out of the ground in mid-December along with the best spinach you’ll ever taste.
How does this magic happen? One tunnel at a time.
Before we dive into the “how-tos,” we need a glossary of terms to help us navigate the winter growing waters (icy as they may be). Winter farmers use high tunnels (also called hoop houses or poly-tunnels). These structures are sometimes referred to as greenhouses, though there’s a clear distinction. Greenhouses are heated. High tunnels are not. The tunnels are generally tall enough to walk through while standing up straight and can range in size from a homemade 50-square-foot version to the Rolls Royce mail order model of more than 2000 square feet.
Winter growers have a few more toolsin their belts, namely floating row covers and cold-hardy varieties that enjoy life at 20 degrees. Floating row cover is essentially a winter blanket made of spun bonded polypropylene fabric. It also goes by the name Agribon or Reemay. The floating row cover is placed over wire hoops that extend a foot or two over the beds. You leave it on your crops like your favorite winter sweater.
The last thing that some growers use is Christmas lights. That’s right. The larger outdoor lights, which can be strung underneath a floating row cover, can give off enough heat to be useful. (Note that they can’t be the energy-efficient LED lights – they have to be old school, energy-sucking ones to qualify as a legitimate heat source.)
Now equipped with our glossary of terms, we can attempt to understand the winter farmer’s life cycle. What DO they do out there while the rest of us hover near the fireplace, waxing poetic about our next trip to Mexico or binge watchingNetflix?
They’re farming of course, with a couple more layers of Carhartts on.
Heidi and Judy Rohwer of Rohwer’s Farm based in Pleasant View, Colorado, at 7000 feet, are in the middle of their fourth year of winter high tunnel production. They start seeding in September and plant successively through the first week of October. Their gamut of winter season vegetables include 10 varieties of lettuce, 7 types of kale, and 3 types of spinach, along with radishes, carrots, beets, onions, bok choy, arugula and a little exotic mild mustard green called mizuna. These two ladies harvest up to 300 pounds of food monthly from each of their two 2000-square-foot high tunnels during the winter season, replenishing their tunnel stash by seeding again in mid-January if the weather is reasonable enough (above 0 degrees).
Heidi Rohwer likes the winter growing season because it sets limits on her “field,” meaning she cannot grow outside the high tunnel, so she doesn’t get overwhelmed by production possibilities. She can simply concentrate on what’s inside. Plus weeding and bugs are significantly less of an issue.
Mary Vozar and Paul Bohmann of Confluence Farm in the Mancos Valley experience similar benefits growing during winter hours. They came up with the idea of growing in the off season long before high tunnels were the “cool kid on the block”in agricultural circles. Studying the likes of Eliot Coleman, author of Four-Season Harvest, they built mini high and low tunnels that they crawl throughto harvest (right now you’re thinking just how lucky you are that you can simply purchase local winter vegetables). With the addition of a 30-by-70-foot high tunnel more than two years ago, they rose to their feet cultivating crops similar to the Rohwers’ and selling at regional markets.
Some of the most pleasurable experiences for both Mary and Paul, as well as the Rohwers, have been tromping through three feet of snow to their respective tunnels and lifting the row covers to find leafy, beautiful masses of edible greens and root crops waving their sweet, flavor-packed foodie flags. “They are completely different vegetables in the winter,” quips Heidi Rohwer. “The cold makes the sugar content higher so they are much sweeter and more tender.”
All this sounds really neat and special, right? But what happens when the thermometer dips into the negative teens? How can a tiny, leafy, fat-free plant survive?
According to Bryan Reed, Sustainable Gardening Instructor at Western Colorado Community College, plants are both thriving and surviving during certain times of the winter. If you can grow your plants to the adolescent stage before cold temps hit and the sunlight ratio drops below 10 hours a day, they will hang out and simply “survive” until the mercury rises and daylight hours increase. Most high tunnel farmers will experience their plants hanging tight from December through mid-February. Then suddenly roots and leaves gain new life force as the calendar turns toward March.
Watering is quite possibly the most interesting part of this whole grand winter food propagation scheme.Evaporation is slowed by the decrease in temperatures, and retention is benefited by the high tunnel and row cover. Watering ranges from once a week to once a month throughout the season. It can be done with overhead watering or with drip irrigation on a warm day.
“High tunnel farming has increased in our region with 33 seasonal high tunnels being built since 2012,” reports Joel Lee, Cortez Natural Resource Conservation Service District conservationist. “Most people are currently experimenting with what works and what doesn’t.” With each new high tunnel built and with the shared experiences of farmers like Paul, Mary, the Rohwers and Bryan Reed, local winter food sources will inevitably continue to grow.
Winter growing offers a chance to grow at a calmer pace and produce a different variety of foods that thrive in colder temperatures. It offers us an opportunity to continue to eat seasonally – creating culinary delights utilizing our winter storage crops of potatoes, onions, and squash mixed with the tunnel offerings of carrots, beets, spinach, and perhaps a topping of spicy mizuna on our dinner plate. Not bad for the middle of winter.