How should I deal with freeze damage to plants?
We’re so glad to see the sunshine and warm temperatures after the blast of the recent winter storm in Dallas. Driving around town, there are many landscape plants showing various degrees of damage and stress, and time will tell whether they will survive or not. This may take a few months, but the good news is that some plants that appear dead may come back to life from the root system.
Once our plants start to grow, we will know which parts to cut away and which plants to replace. Although we can’t speed up the healing process, Mother Nature will come to the rescue soon with warm nights, warm days, and longer day lengths.
Here’s the latest information we have compiled on the plants used in many of our North Texas landscapes.
Evergreen shrubs, such as Pittosporum, Yaupon Holly, and Cotoneasters are experiencing varying degrees of damage. These plants are going to be amongst the most challenging, as they will require time to assess. Fortunately, many already seem to be showing signs of viable buds, so patience will be required.
Azaleas took a big hit, and all blooms are likely lost on most varieties. Foliage is dead too, except on a few varieties and those protected or in select microclimates. Before pruning, we have to wait and see where the shrubs re-sprout - very likely from the ground or below where the snow line insulated them.
It looks like deciduous plants (those that drop their leaves in winter) will be fine, although they may have lost their bloom buds. Oak Leaf Hydrangeas are likely undamaged, but Mophead and Lace Cap Hydrangeas may have different degrees of damage. We’ll prune away the dead once they re-sprout.
Groundcovers like Aspidistra, English Ivy, Ferns, and Liriope may have foliage damage only, but damage to Asian Jasmine could be more severe. We’re hopeful these landscape staples will grow back after the nights get warmer and the days get longer.
Native vines like Coral Honeysuckle and Crossvine should be just fine along with deciduous vines like Wisteria. Carolina Jessamine and Star Jasmine could be damaged, and Coral Vine and Creeping Fig may need to be replaced.
Many herbs like Rosemary and Lavender will be dead and will need to be replaced. Those in containers are always less cold hardy than ones in the ground.
Roses have taken a severe hit, and we will see different degrees of damage. At first glance, it appears that many will freeze back and re-sprout from the snow line.
Most ornamental grasses are cold hardy and will sprout back from the crown as it warms up this spring. A few exceptions are Purple Fountain Grass, Lemon Grass, Napier Grass, and Vetiver.
Bamboo has top damage, and some varieties may not have survived. Hardier varieties like Golden Bamboo and Green Goddess will likely re-sprout at the ground, and we’ll know by early summer.
Although the foliage has been damaged on perennial spring bulbs, and many blooms were lost, tulips seem to have weathered this storm.
Our native plants and wildflowers (Texas Bluebonnets, Texas Persimmon, Texas Redbud, Texas Red Oak) evolved to deal with periodic Arctic blasts and blue northers, and they should not have problems.
Most vegetables were frozen and will need to be replanted including onions, potatoes, and cool-season greens. There’s still time to get in a late crop of cool-season plants like lettuce, greens, cabbage, broccoli, etc.
Spineless Prickly Pear is a very cold hardy plant. It might droop or lose some paddles, but the cactus should recover. Agaves are a mixed bag, and hopefully any limp tissue will give nutrients to the plants. We recommend waiting to cut these back.
There will possibly be dead areas and freeze damage in St. Augustine and Centipede lawns. It’s important not to use pre-emergent herbicides this spring, as they affect proper root growth. We are hopeful that Bermuda Grass and Zoysia Grass should be just fine as they are more cold hardy.
Deciduous trees and shrubs (like Deciduous Magnolias, Dogwoods, Ginkgo, Willows, and Japanese Maples) have shown minimal damage although they may have lost their bloom buds.
They will be different amounts of damage on different varieties of Crape Myrtles in different microclimates, but we hope to see them grow back.
Palms are another story. Most will be damaged or dead, and it will take months to see if they re-sprout. Historically Texas Sabal Palms, Dwarf Palmettos, and Windmill Palms are cold hardy in Dallas. However, Sago Palms are the least cold hardy. We’ll see by July if they survived.
It looks like conifers will be fine, and most fruit trees will bounce back as well. There will be varying degrees of damage on Pomegranates, Olives, and Figs.
We are watching Live Oaks closely. The leaves that would have dropped naturally with the burst of new spring foliage are dropping now, and we are checking for trunk damage that could cause the bark to pop off, leading to severe stress or tree death.
We certainly wish weeds would have been killed during the storm, alas, the cool season weeds survived.
We will update this information as we further assess damage throughout the growing season.