New research out of the College of New Caledonia shows vegetables like lettuce and green onions can be grown in greenhouses during the winter months.
A project was down with the focus of testing the concept of minidomes within a greenhouse and supplemental light. CHC Biology Instructor says these crops tend to have a lucrative sow earlier in the year but can be difficult to grow late season due to lower light intensities. “Our hope was that we could actually produce produce in the fall and early winter that could be sold at a winter farmers market or a backyard gardener who wanted to still produce greens later in the season.” Catherall says, “Normally you just think of root vegetables and storage of those for eating later on, but we really wanted to see if we could push it with green vegetables.”
The research team set up two trials, one in Prince George, and one in Quesnel. They set up different combinations of treatments, such as the addition of low-cost LED lighting, as well as the addition of a secondary cover, or domes over the plants. Catherall says the LED lights had the largest impact on growth compared to treatments that just had natural light. She says installing LED lights enabled them to harvest lettuce and green onions at mature sizes well into December. Catherall says the domes didn’t make much of a difference in growth, and plants without LED lights were much smaller.
Catherall says they would love to try this with other plants as well. “I think a lot of the Asian greens like pakchoi and bokchoi would be an excellent variety to try in this system because they are relatively cold hardy as well,” Catherall explains, “It wouldn’t be applicable to tender plants and heat-loving plants like tomatoes and peppers.”