Although we have officially entered winter, some producers are still growing ample fresh vegetables inside high tunnels, for which NRCS offers funding through EQIP. There are several cold hardy crops that can survive in high tunnels(commonly referred to as hoop houses) over winter without any heating, including kale, cilantro, carrots, and turnips. If you are planning to harvest during the winter, it is important to start seeds a specif ic number of weeks before the last day with 10 hours of sunlight in your location to ensure the crops reach a certain level of maturity before their growth slows down substantially. This chart provides information on planting dates for these crops, whether they can be direct-seeded or transplanted, and includes the level of difficulty for beginners. Row covers can provide additional protection during extreme cold, and multiple layers can be used when temperatures are very low. Some producers remove the covers during the day once the internal temperature of the hoop house has increased to provide more ventilation and increase sun exposure to crops. Around mid- January to early February, once the days are long enough and the soil temperature is consistently above 50°F inside the hoop house, producers can begin germinating seeds for spring harvest.
This time of year, it is important to ensure that snow loads do not cause damage to your hoop house. Roof rakes or soft bristled brooms with extended handles are simple options to gently remove snow without damaging the plastic. Air circulation is another consideration during winter when hoop houses tend to be closed more frequently. The combination of high humidity and cool, wet conditions can cause fungal diseases like downy mildew or powdery mildew on leafy vegetables. When the sun is out, hoop house curtains may be cracked in the daytime to allow fresh air to come in, reduce humidity, and prevent extreme temperature fluctuations that can cause stress for crops. On sunny days, even when the air temperature is very cold outside, hoop houses can
heat up very rapidly. If electricity is available, fans may also be set up to assist with air circulation. Generally, when growth slows down and day length is less than 10 hours, hoop house crops require very little water. Drip irrigation is the preferred method for most producers due to its precision and efficiency in delivering water directly to the roots, being able to easily control the amount, and reducing moisture on foliage. Along with requiring less care, another perk of growing vegetables in the winter is they taste sweeter due to starches being converted to sugars in response to cold temperatures. The below photo shows winter spinach, radishes, and arugula being produced in a NRCS funded hoop house with drip irrigation and row covers at Moon Girl Farm, a diversified fruit and vegetable operation in Pleasant Plains, IL.
FEATURED PRODUCER- MULTIPLE HARVEST LLC
In 2023, shortly after moving f rom Chicago to a 6-acre lot in Beecher, IL , Beatrice Kamau started exploring options to expand her vegetable production business, Multiple Harvest LLC. She visited the Will County USDA Service Center and expressed interest in building a high tunnel. She said, “ They were very helpful because they listened to me, and they said they would like to come and visit the space so they can determine what size of high tunnel I would need. So, we scheduled a day. They came over to the farm in Beecher. We walked the land, and I was trying to explain to them the different conservation practices that I am trying to implement, and they were able to recommend what is doable and what is not.”
She said they were very supportive in walking her through the paperwork and explaining the different forms that were required. The application was submitted in March, and by September she was notified of her approval. She said, “I was excited because I was not expecting it to go through, because that was my first time. I didn’t know they were going to consider my application.”
While her application was being reviewed, she had already done some homework on high tunnel production companies and decided that she liked Nifty Hoops, which offers a “community build” option where a couple of staff guide volunteers in assembling the structure. Since she launched her vegetable production business in Chicago as part of the Urban Growers Collective, Beatrice had networks that she could rely on for assistance. The community build was originally planned for December 5, but they had to reschedule due to snow. Nifty Hoops proposed a date in June, and two of their staff came out the afternoon before to lay the foundation and prep materials. Beatrice said she had 8 to 9 volunteers working in shifts the following day, and they were able to complete the structure by late afternoon. The biggest challenge, she explained, was battling the wind while putting the cover on. She wished she had more volunteers for that, but everything worked out!
Her heavy clay soil, which she described as being like “concrete,” has presented some challenges in her production system. She plans to plant cover crops, and she is currently amending it with wood chips and compost. She said, “I’m using wood chips to suppress the weeds, to retain moisture, and to build the soil… eventually I’m hoping that we will have good soil. Because right now, I have very hard clay, and I have not done any tilling. I like it that way. As much as possible, I will try to do minimal tillage because I just want to maintain the topsoil of whatever area of the high tunnel or any area where I’m going to grow vegetables. I want to be organic and take care of the soil and try to minimize disturbance.” Over the summer, they hosted an educational workshop with Advocates for Urban Agriculture on how to install drip irrigation inside a high tunnel.
Currently, she has a small amount of Swiss chard growing in her structure, but she plans to grow a wider variety next year once she has all her materials in place. According to Beatrice, she plans to use her high tunnel to produce culturally signif icant Af rican crops like jute leaves, amaranth, cowpea leaves, pumpkin leaves, and white eggplant alongside more common vegetables. Most of her sales for this niche produce are direct to customers, which she developed with African and Caribbean communities while growing in Chicago. At that time, she delivered to Yado African and Caribbean Market, and she’s currently communicating with a couple of African grocers in the south suburbs. She also sells larger amounts of tulsi and collard greens to the Black Oaks Center through the Local Food Purchase Assistance program. Moving forward, she has plans to implement agroforestry and alley cropping projects, which has also been awarded funding by NRCS. Beatrice worked with the Savanna Institute to identify which crops would grow well on her land. Some of the ones they selected include pear, apple, plum, cherry, persimmon, blackberry, chokeberry, and elderberry.
NRCS Assistance
Along with extending your growing season, other benefits of high tunnels include improved protection for crops from chemical drift or inclement weather conditions and the ability to reduce water waste and apply nutrients efficiently through micro-irrigation. For more information on assistance with high tunnels, please visit this NRCS website or stop by your local USDA Service Center. Some practices to consider along with high tunnels include: Mulching (484), Cover Crops (340), and Microirrigation (441).
This article was originally published in our January 2025 Newsletter, click here to read the full newsletter.