Growing root crops and leafy greens during winter’s whiteness could be the ticket to putting a little more green in your pocket over the winter months. However, there is a learning curve to growing a crop in a hoophouse after the snow begins to fall.

“There are unique problems in winter growing situations,” says Zachary Grant, extension educator with the University of Illinois Extension. “Even if you’re a farmer [who has been] growing for decades, if you have never had the experience of growing in a high tunnel in the winter it can be a whole new learning curve in terms of planting dates, how you’re direct seeding or transplanting.” For example, he says irrigation is “totally different,” as is ventilation, the latter of which has to be done more carefully to allow for fresh air exchange while not freezing out your plants.

With that said, growing produce in the winter has the obvious advantage of being able to provide fresh vegetables to markets over the winter.

Growers are using various types of structures to grow crops under cover, including high tunnels and low tunnels. Both are interchangeably referred to as “hoophouses.” Call them what you want, the main point is to consider shape, location and the quality of the covering.

Grant says gothic and gable-style hoophouses are a safer bet in areas that get a lot of snowfall. With Quonset-style hoophouses, the snow will fall down the sides and build up, causing the structure to cave in. This is different from gothic and gable-style hoophouses, where the snow falls off. He says for a walk-in style hoophouse, the sides should be angled at 45 degrees to shed snow. Snow melt can also be an issue.

“Snow load is definitely a potential problem,” Grant says. “You need to clear the perimeter of snow buildup. If you allow snow accumulation on the sides and it melts, you’re dealing with rainwater — you need to have good drainage.”

Locate with winter in mind

Wind can certainly be a factor, but Grant is not worried about winter winds where he’s located, about 30 miles south of Chicago. However, he does stress the importance of locating the structures away from trees and buildings that could shade your crop, especially with the sun at such a low angle in the winter.

“You can put it up in June and say, ‘Hey, no problem,’ but then here you are in the middle of winter and a building or tree could be casting shadows,” Grant says. “You can run into some unique problems in site location and design if you’re not careful.”

Grant suggests growers reach out to their county extension agents for information on how to locate and set up these structures. He says you should also weigh the pros and cons of setting up a large structure yourself or hiring someone to do it for you. Hire someone and it could go up in a day, he says, as opposed to three to four weekends if you’re doing it yourself.

Winter cover

Grant recommends standard greenhouse film or woven fabric to cover any type of winter growing structure. There is also a need for another protective layer inside. He says some growers use another layer of poly inside, however, there can be issues with poly.

“The problem is it doesn’t breathe, and it can heat up pretty quickly,” Grant says. “If you can’t get out there to ventilate, it can cause problems.” He says what a lot of growers are turning to is a 20 percent fabric row cover. He says it works as well as poly in terms of providing protection, but it’s breathable, adding that this fabric is one step up in thickness from the row covers growers use as an insect barrier during the summer months. Too thick of a fabric will inhibit light too much.

“Managing that inner layer is really important,” he says. “If you have a week where the sun doesn’t come out at all it is still critical that you remove that inner layer and allow circulation.”

No rest from the wicked

Just because it’s cold enough outside to numb your hands doesn’t mean there isn’t disease pressure and even weeds inside these structures. Grant says downy mildew on lettuce and spinach can be an issue in a winter hoophouse, and he’s even seen chickweed that had to be plucked. Good ventilation is the key to preventing fungus problems, he says, as are organic-based fungicides.

Feeding the student population

The University of Illinois has a production and learning facility for produce growing and marketing on campus. Matt Turino manages the Sustainable Student Farm at the University of Illinois Urbana-Champaign. The facility consists of three 30-foot-by-96-foot greenhouses run by students, workers and volunteers. Turino says they can produce fresh greens and tomatoes for nine to 10 months out of the year. Winter growing can be a challenge, but it’s worth it as it means fresh produce for students in the dining hall on campus.

“Growing in winter can be significantly more challenging than growing in the season they like to grow,” Turino says. “There is more labor per product, but you can get a better price during winter, and if you’ve got workers you want to keep year-round, it’s a good way to dial in your winter production.”

The farm starts winter greens, including spinach, baby bok choy, baby lettuces and kale in the fall and are able to bring several harvests of the greens into the dining hall over the winter months. Turino says they don’t start greens during the winter months mostly because they don’t have a frost-free water line close to the houses. The winter crop is over in March, at which time they start tomatoes and other spring crops.

“A good place to start is with spinach [because] it’s the most hardy,” Turino says. “It’s a little bit harder to establish, doesn’t compete against weeds as well, but if you can take care of it, it will keep chugging. That and baby kale are the true workhouses.”

Like Grant, Turino emphasizes the importance and challenge of timing winter crops, something that is a little tricky when there still might be summer crops in the greenhouses in late fall or you need to get ready for spring and need to move a winter crop out.

The routine at the farm is to start a different crop in each of the three greenhouses: one in the late fall for winter harvest, one devoted entirely to hardy spinach and one with a mix of greens.

Instead of using organic matter, such as compost that many hoophouse growers use, they rely solely on cover crops to provide nutrients and replenish the soil. Having moveable greenhouses allows this system to work reasonably well.  

“I really like the moveable aspect of the greenhouses,” Turino says. With this method they’re able to start a crop on one side, and plant a cover crop consisting of oats, buckwheat and sorghum sudangrass, on the other. If they can time it right, they’ll sow rye and vetch in the fall for a winter cover. They do this on a yearly basis starting in the late fall. Turino says he thinks being able to move the structures back and forth mainly helps with disease control, but also allows them to flush out salts with rainwater on the uncovered growing plots.

Their biggest challenge to a successful crop, however, is ventilation. It’s finding a balance between controlling moisture buildup and freezing out a crop.

“The big thing is balancing so there is enough air flow for moisture reduction and making sure the plants stay warm enough, which is often counter to each other,” Turnino says. “Putting fans in tunnels helps. Don’t leave anything covered too long — provide good air flow and keep the plants warm.”

Keeping the plants warm and cozy over a long Midwest winter is helping to provide fresh produce to the students at the University of Illinois while teaching the student body how to grow under cover.

Neil is a horticulturist and owner of Green Industry Marketing. greenindustrywriter.com

On cloudy days, growers at Green City Growers in Cleveland kick on LEDs to give their lettuce and basil an extra boost, speeding up the growing process and improving the plants’ look and taste.

Green City Growers encompasses 3.5 acres of indoor growing space and producing millions of nutritious plants annually. The cutting-edge urban hydroponic greenhouse — headquartered in the Central neighborhood on Cleveland’s East Side — is counting on high-tech LED lamps to increase plant production during Northeast Ohio’s long and gloomy winters.

GCG installed 1,200 LED lights at the beginning of 2018, switching from the metal halide and high-pressure sodium (HPS) lamps it had been using for the previous four years.

“When we opened [in 2013] there wasn’t a version of LED fixture that was commercially viable for a facility as big as this one,” says John McMicken, CEO of Evergreen Cooperatives, which includes a solar energy business and laundry co-op along with Green City Growers. “We started with high-pressure sodium, which has always been the tried-and-true version of agricultural lighting.”

LEDs mean plant food

Inside the massive greenhouse, the new lighting system helps cultivate 3 million heads of lettuce and 400,000 pounds of basil annually, with GCG’s hearty greens sold to local and regional restaurants, grocery stores and food processors.

Unlike traditional greenhouse lamps, LED lights save energy and are more easily absorbed by plants during the photosynthesis process. Pigments in the leaves harness the LED color spectrum — which growers change onsite depending on the weather — mimicking the sun’s rays and ideally resulting in the best possible produce.

“LEDs give us the ability to control the intensity of the lighting, where HPS lighting is either ‘all on’ or ‘all off,’” says McMicken, who also currently serves as the greenhouse’s interim president. “We might need more light at the younger side of the crop, and less light at the more mature side. With LEDs, every fixture is IP addressable via a Wi-Fi network, so we’re able to control groups of lights at a time. We tell our growing team how much light to add depending on the amount of natural light available, which changes throughout the day. Now we have more flexibility on how and when to use the lights based on what Mother Nature gives us.”

Specific plants require individualized wavelengths from the light spectrum, McMicken says. Younger crops benefit from red lighting, while mature plants that don’t need as much light like the blue spectrum. Good lighting is a particular boon for basil, driving oil content within plant tissue to turn out a nutrient-rich emerald green blend.

“LEDs help us ensure year-round consistency in size as well as flavor and color,” McMicken says. “That’s mission-critical for [our customer] Nestlé that’s selling high-end recipes.”

Testing, testing

In 2017, Green City Growers evaluated LEDs from 10 different manufacturers, choosing a Canadian company specializing in outdoor- and water-rated fixtures. Many LED systems are air- or fan-cooled, which poses a challenge for a high-humidity greenhouse environment.

Installation presented an immediate challenge, considering an operation where plants at various stages of growth are floating in shallow pools of water in a deep-flow technique system. Eschewing ladders or lifts, the Green City Growers team instead built an aluminum boat ramp across a wheeled track, sliding the contraption back and forth to mount lights along the ceiling.

Though LEDs are costly upfront, the potential for yield increases is reason enough for the investment, McMicken says. An improved growth process means more produce for customers and revenue for an employee base in need of living-wage jobs. Green City Growers shares profits with its 45 employees, carrying a larger goal of wealth creation for the economically depressed community in which it resides.

The greenhouse is currently training employees on the lighting system, providing additional transferable skills to further workers’ high-tech agriculture careers.

“We’re always looking for ways to diversify and expand the career path of our employees,” McMicken says. “This [LED system] has absolutely opened up new doors for us.”

Now that the greenhouse is 100 percent LED-lit, McMicken is excited to witness the impact of next-generation lighting technology on his operation’s bottom line. Based on a projected yearly 15 percent increase in crop production, the co-op CEO forecasts a $600,000 uptick in annual revenue, heralding what he believes to be a bright future powered by LED lights.

“It’s a game-changer for the business,” McMicken says. “I envision most if not all growers converting to LEDs if they haven’t already. In a few months, we’ll know the true impact.”

Douglas is a Cleveland Heights, Ohio-based freelance writer and journalist. His work has been published by Midwest Energy News, Crain’s Cleveland Business and The Chronicle of Higher Education.

Food safety recalls have become a constant in the fresh produce industry over the past several years. While the general public may hone in more on meat recalls (especially beef recalls) because of their frequency, recent produce recalls have garnered increased attention. It’s not necessarily that there are more recalls due to foodborne illnesses and contamination than before, but they’re being detected and addressed quicker — and more publicly due in part to social media and advancing technology. Romaine lettuce was recalled because of E. coli contamination multiple times in 2018, including two outbreaks that infected consumers between March and June, and again in October and November, according to the Centers for Disease Control and Prevention (CDC).

Even though greenhouse-grown romaine wasn’t the culprit in the most recent recall, growers mustn’t become complacent about their food safety practices. Greenhouse production is, in general, much less prone to food safety problems than field growing, but there is still potential for contamination — and serious repercussions.

In this month’s cover story, we’re taking a proactive approach, and looking at the steps you can take to ensure your greenhouse is a clean, food-safe setting, and avoid a recall. Lisa Lupo, food safety expert and editor of sister publication Quality Assurance & Food Safety (QA) magazine, shares her insights as well as those of food safety specialists from The Ohio State University and Virginia Tech here.

However, as greenhouse growers, you have a marketing advantage — in late November 2018, the Food and Drug Administration (FDA) commissioner Dr. Scott Gottlieb emphasized the fact that greenhouse-grown romaine was not involved in the most recent outbreak. The FDA also announced a voluntary labeling agreement for romaine lettuce growers that denotes the product’s harvest date and location, which could be another opportunity to emphasize its greenhouse origins. Your produce has become more valuable and more trustworthy in the eyes of the FDA, and potentially the consumer. In her Edible Insights column, Leslie Halleck examines how greenhouse growers might benefit from the new voluntary labeling agreement.

If you’ve considered incorporating lighting into your operation, you won’t want to miss the 2019 Lighting Guide. In it, we bring you some of the latest research in lettuce, tomato and cucumber crops, and profile a Cleveland grower whose purple lights have caught the collective eye of the surrounding community. Check it out starting here.

kvarga@gie.net | (216) 393-0290

Twitter: @Karen_GIE

Photo: Adobe Stock

No label? Don’t eat it. That’s the advice the FDA recently gave consumers about how to proceed when buying romaine lettuce. I suspect such a directive, coupled with the fear caused by the recent E. coli romaine outbreak, may eventually influence consumers to apply that advice to other food they buy. For produce growers that means investing in new labeling or updating existing labeling, voluntarily. In previous columns I’ve written about the need for transparency when it comes to food labeling. The name of the game in 2019 seems to be traceability.

You might not think inspiring confidence is part of your job when you’re a lettuce grower. You’re just supposed to grow really good lettuce, right? The romaine outbreak should serve as a wake-up call to all growers that while American consumers will ignore a host of safety issues with other products proven to be far more dangerous — they completely freak out about food safety issues. All it takes is reports of a couple people getting sick, and your produce is off the shelf and banned in restaurants, whether that reaction is warranted.

Traceability is a system that ties produce to the exact field or greenhouse in which it was grown, using unique codes. Without a traceable label, there’s no way for consumers or wholesale buyers to separate your safe produce from produce linked to a geographically identified outbreak. These days, you’re selling both really good lettuce and the confidence that it is safe.

The FDA hasn’t mandated it yet, but it is urging growers, processors, distributors and retailers to clearly and prominently label all individually packaged romaine products to identify growing region and harvest date. They’ll most likely urge you — or require you — to do exactly the same thing for the next food crop that gets contaminated, be it beans or broccoli. So, why stop with romaine when it comes to transparency and traceability? It’s probably worth it to you as a grower to take a proactive comprehensive approach with all of your crops.

We all want authenticity and transparency when it comes to the food we eat. Traditionally, source or origin labeling was most meaningful to the consumer in regard to the organic and local food movements. As we grew more concerned about how — and how far away from home — our food was grown there were big benefits for growers willing to invest in more detailed labels and packaging. We now need to know exactly where the produce was grown, with a harvest date, to avoid potentially lethal food poisoning. If the grow-organic or grow-local movements didn’t move you to traceable labeling, perhaps food poisoning should.

Detailed labeling provides the consumer the opportunity to learn more about how and where their food was grown. That’s in addition to the brand exposure benefits growers garner from detailed packaging or POP (point of purchase) material. For consumers to feel safe, they may want to develop a more direct relationship between the produce they buy and who grows it. When there is a label that provides the grower information and location, consumers can research you online or with distributors.

A big bonus for greenhouse and hydroponic growers? The FDA is telling consumers not to worry about the romaine grown using these methods. That sends a strong message to consumers, regardless of the crops you’re producing. Hydroponically grown food has traditionally faced significant marketing challenges from the organic food movement. In the face of field crop contamination, hydroponically grown produce offers clear safety and sustainability advantages. You can now shout it loud and proud if you’re growing under glass hydroponically.

Traceability can not only create a great marketing opportunity, it can also help you improve your systems and reduce losses. When there is a contamination outbreak or other issue, having traceable lots helps you determine whether or not they should be recalled. It can also help you better manage your inventory and improve turns. When there is a general customer complaint about quality, you can trace such complaints back to specific harvests.

Now, let me say that I am of course conflicted about adding more packaging and labeling to bulk produce. The last thing this planet needs is more plastic. In fact, packaging guilt is a big reason I choose to grow more of my own produce at home. I get heart palpitations trying to make sure all that produce packaging is recyclable, or even worse, throwing it away if it’s not. I’m not suggesting that all produce not currently packaged should be just so it can have a label.

For bulk produce we can at least make sure vendors have the POP they need to communicate to the end customer exactly where and by whom the produce was grown. Good signage that identifies the grower and specific growing location with traceability information, should be the norm. That’s exactly what the FDA is urging growers do with bulk unpackaged produce.

As always, no matter what you’re growing or selling, communication is key. The more information consumers have about where and how their food is grown, the better chance you have at cutting your losses to foodborne illnesses.

Leslie (CPH) owns Halleck Horticultural, LLC, through which she provides horticultural consulting, business and marketing strategy, product development and branding, and content creation for green industry companies. lesliehalleck.com