After a relatively mild start to the season, significant snow is finally beginning to fall here in Indiana. Midwestern winters are one of the most common complaints of its inhabitants, and I myself could certainly do without negative degree wind chills. However, before we dismiss the season entirely, winter actually does serve an important role in the Midwest and is one of the reasons this area is so suited for certain types of agriculture. Among them, farmers are certainly hoping for some more moisture to come our way, in the hopes of replenishing our rather dry soil.
The severity of the winter will actually play a role in some of the key indicators that predict the success of the following season’s field crops. Cold winters result in a deep freeze in the soil that kills several insects and pathogens that are trying to overwinter and become pests again the following spring and summer. For one example, the sweet corn disease Stewart’s Wilt is transmitted to the plant via the flea beetle, which overwinters in the soil, then feeds on young corn plants in spring infecting them with the disease. The likelihood that the beetle survives the winter is based on temperature. As a rule of thumb, if you add the average temperatures of December, January, and February, and that number is less than 90, a Stewart’s Wilt outbreak is highly unlikely. However, if that number is greater than 100, it could be an indicator of a severe outbreak.
Orchard farmers are also rooting for a cold, consistent winter due to a process known as vernalization. This is a term that applies to several plants, for instance fruit trees, and has to do with the fact that these plants need a period of cold to go dormant in order to properly flower the following spring. Winters without an adequate number of days when the temperature does not get below 45 degrees result in flower buds failing to fully develop leading to an insufficient crop. I also want to point out that it is key for these temperatures to be consistent, as one of the worst things that can happen to fruit trees is to have an unseasonable warm period before winter is completely over, causing the tree to break dormancy and flower, only to have those flowers killed by a frost once temperatures drop again. This can completely wipe out a fruit crop.
Homeowners and gardeners can also be affected by vernalization as several flowers, such as tulips, daffodils, and hyacinths require a dormant period or risk growing severely stunted flowers. It will also affect biennial vegetables such as beets, cabbage, and brussel sprouts.
In summary, aside from enjoying sledding, snowball fights, or the sensation of a warm fire, remember to appreciate that the cold weather will also play a role in how big and how expensive your slice of pie may or may not be later that year.