Vegetable Season Extension

Last week felt more like August than late September with the high temperatures and lack of moisture. With the heat, it’s hard to think about frost, even though we are just a few weeks away from our 50/50 chance of having a nighttime temperature of 32 degrees. Although we are entering October, there is still some growing season left, and there are ways to keep growing vegetables even beyond the first freeze. Let’s take a look at some options to extend your gardening season.

There are many ways to extend your vegetable growing season, whether you are trying to develop later in the fall or start growing vegetables earlier in the spring. One of the easiest methods is to utilize floating row covers over the top of the plants, similar to the photo on the right. Floating row covers are spun-bonded polyester or polypropylene fabric that comes in various thicknesses depending on what you plan to use it for. You can use the fabric to create a low tunnel with hoops to hold the row cover over the top of the plants. Floating row covers will keep cool-season crops warm during frosts, including under snow; however, there are limits to how cold floating row covers can keep plants warm. This option keeps the plants warmer, and thinner fabrics can also be used to exclude unwanted insects during the growing season.

Cold frames are another option for extending the growing season by starting plants in the spring and allowing you to grow cold-tolerant vegetables late into the winter. Cold frames are typically low wooden boxes or frames with glass (often old storm windows), polycarbonate, or polyethylene film covers, which are set in the soil or over beds in the garden. Cold frames are usually constructed with a sloping top and set facing the south to capture the most winter sun. Tops may also be peaked or arched with hoops that support a polyethylene film covering. Polyethylene film is the same as plastic sheeting, but a special greenhouse film is used for cold frames and high tunnels. It is typically six mils thick and is treated with a UV-blocking material to last at least four years.

Low tunnels are hoop-supported row covers that are too low to walk in. Tunnels high enough to walk in are called high tunnels. Low tunnels may be covered with polyethylene film or floating row cover and may vary in width to span a single row or one or more beds in the garden. Floating row covers of varying weights can be used during much of the year and replaced by polyethylene film during the winter. Lighter row covers can be used during the spring and summer, and heavier row covers can be used in the late and early winter for freeze protection. Greenhouse polyethylene is preferred for covering in the winter because it can be saved and reused from year to year, but standard 6-mil polyethylene may be easier to obtain.

Fresh vegetables are a staple of many households, and there are many ways to extend the growing season past the first frost well into winter. Last winter, I had a broccoli plant that survived all winter under leaves to be eaten in the spring. Try one of these season extension ideas this fall in your garden today.

Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.

Phone: (316) 321-9660

Email: callae@ksu.edu