The Texas Winter Storm of 2021 was one for the record books, the first billion-dollar weather disaster of a long and severe weather year https://www.ncdc.noaa.gov/billions/. Not all those billions of dollars were made up of plant related losses, but billions of plants were lost on farms and in landscapes in North Texas.
While we can’t control the weather, there are some simple things that we can do to help our plants make it through whatever this winter brings.
Top Tips for Winter (plant) Wellness
- Turn off the irrigation system
You too can save thousands of gallons of water with one finger. In the winter months, precipitation often exceeds the amount of water that mostly dormant North Texas landscapes require. Excess irrigation can contribute to disease development and unnecessarily large water bills. Save water and your irrigation budget for when it is needed most. There is another big benefit to turning the system switch to the off position: avoiding l man-made ice events and any subsequent accidents.
- Mulch
There is a reason that leaves fall before winter. Using leaves as mulch is a simple and effective way to recycle organic material and improve the landscape. Leaves can be used as mulch in vegetable gardens, flower beds and around shrubs and trees. Apply a 3-to-6-inch layer of shredded or crushed leaves around the base of trees and shrubs. Avoid the dreaded mulch volcano effect by keeping mulch away from tree trunks and shrub crowns. In annual and perennial flower beds, a 2-to-3-inch mulch of shredded leaves is ideal. Mulching is especially important in establishing newly planted trees, shrubs, and perennials. If the natural look of shredded leaves isn’t what you like, top off the leaf mulch with a thin, inexpensive layer of bark mulch. You’ll get all the benefits of bark at a fraction of the cost.
- Water right before a freeze
When extremely cold temperatures are expected, watering plants thoroughly before temperatures drop will hold heat in the soil. A “wet cold” may be unpleasant for people, but it is warmer than a “dry cold.” Moist soil holds about four times more heat than dry soil and the air temperatures above moist soil can be as much as 5°Fwarmer than air temperatures above dry soil. Mulch will help hold that moisture in the soil and minimize temperature fluctuations in the root zone.
- Prioritizing plant protection
Many of the most commonly used landscape plants in North Texas come to us from even colder climates and will make it through our cold weather just fine. Our North Texas native plants should be able to handle our “normal” winters. Tropical and subtropical choices such as palms, cycads, and citrus will definitively need extra help.
The winter annuals most frequently planted in North Central Texas: pansies, violas, and ornamental coles such as cabbage and kale, are suitable for planting all way into USDA Hardiness Zone 4 where temperatures fall to -20 F. While they may slow down a bit in cold weather, they’ll be up and blooming again soon.
The relative cold hardiness of annuals brings up another important point. Plants that only live one year are often not protected because they will be replaced in a relatively short time anyway. Save time consuming cold protection practices for more valuable, longer-lived specimens.
- To cover or not to cover
As people pile on the extra blankets to hold in body heat, they often want to pile covers on their plants. While a person can bundle up and hold in body heat, the heat that a plant cover can hold in is going to come from the ground. Therefore plant coverings must be large enough to cover the plants all the way down to the ground and must be anchored. Rocks, bricks, and container plants can be convenient anchors. It is ok to use old sheets and blankets for covering, but non-woven frost protection fabrics offer several benefits. They consistently provide 2-4 degrees F of protection and transmit enough light to plants to keep them photosynthesizing while covered during prolonged periods of cold weather. Plastic covering should only be used on a frame that keeps the plastic above the plants. A string of Christmas lights can be used to provide additional heat under this type of cover. Old-fashioned C7 lights under plastic covered frame can raise temperatures by as much as 18 degrees F.
- Consider containers
Plants in containers are more susceptible to cold damage than those with roots in the ground. On the other hand, because they are not in the ground, they can be moved indoors or at least into a more protected outdoor area such as under a covered patio. Simply grouping containers together will help them stay warm. Covers placed over containerized plants should reach all the way to the ground, just as they should for in ground plants to hold heat that will radiate from the soil or driveway or patio surface.
- Prune prudently
Trees should be regularly pruned to minimize the potential for damage during snow and ice storms. The strongest tree has a central leader, or a trunk that extends all the way to the top of the tree, and branches that are attached at wide angles. A nearly horizontal branch is not more likely to fail than one that is nearly upright. Dead branches are going to fall eventually, and even a light snowfall can knock them right out of a tree. Always prune to remove dead or damaged branches as soon as you notice them and to avoid additional damage to people, plants, and power lines below. Hiring an ISA Certified Arborist is the best way to protect the largest and most valuable components of your landscape. Find one at https://www.treesaregood.org/
Cutting back herbaceous perennials such as salvias, buddleias, and Turk’s Cap after the first hard freeze and applying fresh mulch over their roots will help them survive the winter. Ornamental bunch grasses can use frozen foliage to protect the growing points of the plant which are down at the base of the clump. Another benefit to not cutting back ornamental grasses until new growth comes out in the spring is the color and texture that they continue to provide in the landscape.
- Get outdoors!
Both you and your plants will be healthier if you spend time outdoors even in cold weather. Take time to enjoy those brave winter bloomers and tough trees and shrubs.