Gardening Tip of the Month: Frost Damage Prevention and Treatment
Winter is upon us here in Tucson, so it’s time to start thinking about protecting your plants from frost damage. Although we don’t see much snow here in Southern Arizona, it’s still entirely possible that your plants will suffer from the ravages of cold weather. Although the cold is already beginning to set in, you still have time to take steps to protect your plants from frost damage. If you suspect that your plants are already frost-bitten, this blog post can help you save them.
Frost Damage Prevention
Although the majority of the plants we use in our Tucson landscaping projects are designed to be hardy to low temperatures, you should still pay attention to the condition of your plants during the winter. The two keys to preventing frost damage are proper plant selection and plant placement. If you’ve lost plants to frost damage, replace them with hardier plants that are more tolerant of the cold, like agaves. If you do want frost-sensitive plants in your Tucson landscape, consider microclimate areas in your yard to plant them. Areas close to the house or under the shade of the roof tend to be warmer than areas that are exposed and farther away from your house, and block and masonry walls, in addition to rocks and patios, collect and reflect the heat of the sun. Bring smaller potted plants inside your home or in your garage when the weather gets really chilly. Also, never cover plants with plastic sheets or tarps, because this can actually worsen the effects of frost damage.
Frost Damage Treatment
If your plants do suffer the effects of frost damage, luckily there are ways to minimize the extent of the damage and possibly save the plant. Although the signs of frost damage may vary from plant to plant, generally the symptoms of frost damage involve blackened leaves which eventually shrivel up and die. Often, the extent of frost damage will not become evident until the spring comes and is often difficult to detect on certain trees and shrubs. Once you identify frost damage on your plants, wait until late February to mid-March to prune the damaged sections from the plant. This waiting period is important because the frozen leaves can provide additional insulation from the cold. When you decide to prune, make sure you understand the plant’s growth habits and start at the smallest dead branches. Use your thumb or a knife and lightly scratch the surface of the branch to help you determine the color of the underlying plant tissue. If the cambium below the bark is green, the tissue is alive. If it is black or brown, it is frozen tissue and probably dead. When you find green tissue, you will know that it is safe to cut back to that point.
If you have any other questions about frost damage and treatment, contact Horticulture Unlimited. We have been providing landscape design services to the people of Tucson and Southern Arizona since 1979. If you have any questions regarding your residential or commercial landscaping, contact us at 520-321-4678 or visit our website for more information!