The corn root beetle is not confined to large agricultural crops; it can also invade home gardens and ornamental flowers. Fortunately, this pest has a limited life cycle, with only one generation per year. In the fall, female corn root beetles lay their eggs in the soil around corn plants. These eggs hatch the following spring, and the larvae begin feeding on the corn plant roots. By midsummer, the larvae pupate, and adult beetles emerge in search of pollen, primarily from corn silks, though they can also damage corn leaves. As the corn plants dry out later in the summer, the beetles seek other pollen sources, often targeting squash, cucumbers, pumpkins, and unfortunately, ornamental flowers such as dahlias, roses, and zinnias. They particularly favor lighter-colored blooms, causing extensive damage that can ruin the petals.
Effective management of corn root beetles involves integrated pest management strategies. Rotating corn crops annually, maintaining a distance of at least 10 feet from previous crop sites, helps break the beetle’s life cycle. Additionally, using biologics, managing weeds, and applying select soil pesticides can assist in controlling infestations. For agricultural producers, corn root beetles pose significant economic challenges, and for home gardeners, they can severely impact flower yields and health. With some planning and proactive mitigation efforts, it is possible to keep the corn root beetle populations in check
Last summer, in 2023, I undertook the task of growing the flowers for my daughter’s wedding, a project that initially seemed straightforward. I planted a variety of flowers—zinnias, dahlias, amaranth, hollyhocks, cosmos, celosia, and gomphrena—alongside corn to make the most of the garden space and to grow more vegetables. With limited experience and a constrained garden location, I didn’t realize the potential issues of planting corn so close to the wedding flowers.
At first, everything appeared to be going well. The corn germinated robustly, and the flowers started to sprout. I planted them later in the season to ensure ample blooms for the October wedding. While the dahlias were slow to start, by early August, both the corn and flowers were flourishing, with the dahlias beginning to grow in size.
In a bid to save the flowers, I tried an insecticide, but it proved ineffective. Realizing I needed another approach, I covered the dahlias with organza bags—sheer fabric pouches designed to protect blooms from pests. These bags worked by physically blocking the beetles from reaching the flowers. Once the lighter-colored blooms were covered, the beetles shifted to other pollen sources, but the damage was already extensive.
Fortunately, my initial overplanting, due to my inexperience, ended up being beneficial. On October 14th, the weather was perfect, and my daughter’s wedding was a beautiful event. Despite the challenges with the beetles, the flowers looked lovely, thanks to the organza bags and the extra blooms from my overplanting. The day was a success, and seeing my daughter’s happiness made all the effort worthwhile.