The cover crops, spring oats and crimson clover, seeded on October 4 in our “treatment” high tunnel have established very well. The spring oat crop is expected to winter kill and the crimson clover will continue to grow until termination in the spring. The outside temperature reached an overnight low of 24 degrees F prior to when this photo was taken, and the spring oats showed no signs of damage but later in the winter when more sustained cold temperatures in the upper teens are prevalent, winter kill should occur.  

Along with seeding cover crops to overwinter and create a habitat for retention of beneficials, cut flowers were also grown in this “treatment” tunnel as part of the HR 133 grant, Strategies for Improving Biological Control of Insect Pests for Vegetable Growers Utilizing High Tunnels. Three of the five cut flower types, celosia, sunflowers and zinnias, have been removed from the tunnel. The two remaining flower types are lupine and stock. The lupine did not flower in year one but is expected to produce flowers in the second season. The stock likes cooler temperatures and while they didn’t really produce many flowers during the summer growing season, the remaining plants are really flourishing right now. Cover crops seeded the end of October in the area where the three cut flower types had been removed have also germinated and are starting to establish. Insect monitoring will give us an idea of what predators and pests are overwintering within the tunnel.

Photo credits: B. Aly, Illinois Extension 2023