Now that the cold weather is finally here, this is a great time to refresh on protecting our landscape plants from the cold temperatures.
Before we dive into that, I want to point out some general practices that we should all be implementing as we move from fall into winter. Although many plants are still growing, some things go dormant, or slow down during the shorter days and cooler weather.
Make sure you are adjusting your maintenance practices as well. The primary one being watering; while your lawn may still require some water, the majority of landscape plants dramatically reduce their water needs during this period. Check soil moisture by touching them, and do not water unless it feels very dry and/or you see signs of wilting.
Our mostly sub-tropical climate and unpredictable weather often leave us unprepared and with little time to protect our plants. But these easy tips can help you save many of your plants.
If you are a native plant lover, you won’t have much to do. Cold weather resistance is another reason to utilize native plants in the landscape. While we don’t get freezing temperatures that often, native plants are adapted to tolerate these drops in temperature.
However, as we live in a sub-tropical region that allows us to grow a variety of both sub tropical and tropical plants most of us have a non-native or two in our yards. If you find yourself in the latter group here are some tips for protecting your plants when the temperatures drop below 32 degrees Fahrenheit.
Water can be a tool to protect plants from cold weather, if applied properly. Water actually helps maintain soil temperatures. However, excess moisture on the leaves and stems can cause further damage as the water begins to freeze. Do water the soil, don’t water the plant leaves and stems. Additionally, water needs to be applied while temperatures are above 45 degrees Fahrenheit, and remember to turn off your irrigation systems if freezing temperatures are expected.
Hopefully you thought about the possibility of freezing temperatures when you planted your extremely cold sensitive plants and they are on the south side of your home or behind a wind break protecting from northern winds. If not, covering them with a sheet can temporarily help retain soil heat in freezing temperatures around 32 degrees Fahrenheit; cardboard boxes and large plastic trash cans work too. Keep in mind that the cover is helping trap the heat rising from the soil, so if you wrap your plant it won’t provide the same protection. You need to drape the cover over the plant so it touches the ground on all sides and secure with something heavy. Remember, once temperatures rise above freezing or the sun comes out uncover the plants.
For mildly cold sensitive plants, a 4-inch layer of a woody mulch may provide sufficient protection. Potted plants can be moved indoors or grouped together against a structure and covered with an old sheet.
Once temperatures return to normal you will be tempted to go out and prune back the damaged plants. Restrain yourself for a couple of reasons, first of all the plants just went through a shock and pruning will only further shock the plant. Second, we may have more cold weather and those damaged leaves may provide some additional protection.
Give the plants time to recover before you prune, perennials might look dead, but the root systems may be alive and well below the surface. For shrubs and small trees it may take months before you can tell what the real damage is. Wait until you see new growth and are well past the possibility of more freezing temperatures before pruning.
For a more information on frost and freeze damage in plants check out this Extension Publication: https://aggie-horticulture.tamu.edu/travis/wpcontent/uploads/2013/06/FrostsandFreezes.pdf.
Ashley Gregory is the Horticulturalist for Hidalgo County with Texas A& M AgriLife Extension Service. She can be reached at the Hidalgo County Extension Office at (956) 383-1026 or by email at firstname.lastname@example.org.