| Lubbock Avalanche Journal
February is the coldest month in the northern hemisphere – confirmed this week in Lubbock with the Arctic Blast that has just been experienced. We have weathered some of the coldest temperatures our region has seen in decades. As a result, concerns have been raised about what to do if the extremely cold temperatures occur again.
Hopefully Lubbock AJ readers have followed the overarching gardening principle in adding plants to a landscape that contains only wood samples adapted to their respective USDA hardiness zone. Winter hardiness zones are geographically defined areas in which plants can survive a minimum temperature. Since Lubbock is in Zone 7, it is expected that plants robust for Zone 7 can survive 0 ° F.
Woody plants, trees, and shrubs that are adapted to Zone 7 and still at rest should have survived this Arctic explosion with little or no damage. Other herbaceous perennials, which usually hibernate without damage, may be vulnerable to prolonged exposure to freezing temperatures and may not have survived without winter protection.
Frost cloths offer the best protection for winter plants from frost damage in winter. They are sold differently as frost blankets, thermal blankets, garden blankets, garden fabrics, frost protection blankets and insulating blankets.
The degree of protection varies with the thickness of the fabric. Some frost wipes up to 12 mils thick offer up to 4 degrees of protection, while the thickest wipes offer 10 degrees of protection. Thicker, heavier cloths are sold as anti-freeze blankets and come in rolls 10 feet to 50 feet wide and up to 500 feet long.
The fabric of most frost wipes is made of polypropylene, which allows light from the sun to penetrate. Frost cloths work in two ways: protecting against freezing night temperatures and, since the cloths are translucent, increasing daytime temperatures under the cloth by capturing the day’s radiant heat energy.
The frost cloths used in our gardens and greenhouses were purchased locally at garden centers from hardware stores and ordered from Gardeners Supply catalogs at gardeners.com (800) 476-9715 and Growers Supply at growerssupply.com (888) 833-1412.
For some degrees of protection, other covers such as plastic pots, linen bags and sheets can be used. For these two layers, lay over plants as the air between the panels will provide insulation. Do not use plastic wrap, as these will quickly absorb heat during the day, warm the plants, but quickly lose heat and then freeze again, resulting in damaged foliage.
The delicate herbaceous plants in the photo grow in an unheated greenhouse that is protected from the 0 ° F temperature with several layers of thick frost cloth.
The good news is: Persistent freezing temperatures for at least five days can be fatal to some insect populations.
Ellen Peffley taught college horticulture for 28 years, 25 of them at Texas Tech. During this time she developed two types of onions. She is now the sole owner of From the Garden, a gardening farmette. You can email her at Gardens@suddenlink.net