If you’re a plant, and if you were growing in Texas last week, you’re probably wondering what hit you. At a time when Texans were worrying about plumbing and highways, plants were struggling to stay alive.
Let’s start with “patience.” Don’t assume that just because a plant’s leaves have all turned brown that that plant is on its way to the compost. That may not be the case and you might be throwing away good plants and good money if you start cutting them out prematurely.
Stems and twigs are much better benchmarks. Scratch the bark tissue to see if the wood is both moist and green. If it is, then that twig is probably going to put out new leaves within a few weeks.
Landscape contractors and nursery professionals will check for split stems first if they’re trying to determine if certain plants have been frozen. Stem tissues that have been frozen will split lengthwise (parallel to the sides of the stems). It becomes evident within just a few days of the cold weather’s abating.
Finally, twigs will become dried and brittle when they’ve been killed by the cold. Instead of being supple and flexible when bent, dead twigs snap like dry straws. That’s evidence that they can be trimmed away without further delays.
Specific plants and their symptom
I’ve spent much of the past 10 days looking at landscapes and answering questions. Here are several plants about which many have asked, along with guidelines of what they will look like if the cold might have hurt them.
Sago palms (Cycas revoluta). These aren’t really true palms, and they’re also not truly adapted outdoors here in the Metroplex. They’re winter-hardy into the 20s. We missed by 25 or 20 degrees this time. Trim off the dead leaves and wait if you wish, but I’ll bet that they won’t be coming back.
Prickly pear cacti (Opuntia sp.). You’d think nothing would bother these plants, but last week knocked them out cold. I’ve been amazed at how many people had the spineless form growing in their landscapes. But, that’s “had” in the past tense. They’ve quickly turned to mush, suggesting they’re not good plants for North Texas.
Century plant (Agave americana). Here’s another tough-as-nails xeric plant that met its match last week at record cold temperatures. Its leaves have lost their strength. They’ve now collapsed and are oozing zap. What we are seeing is precisely why “native” plants aren’t native over all of our state – just where they’re adapted. And it’s not here.
Nandinas. These are some of my own personal “go-to” landscaping stars. I’ve mentioned before that I’ve used “Compacta” nandinas as a mainstay intermediate shrub in several places in my landscape. We had just trimmed them to remove the leggy stems three weeks ago, and now almost all of the remaining leaves have been torched by the cold. But the plants will be just fine. I’ll give them a week, then I’ll brush them with a broom to knock off the dry leaves. If I have to trim any more, I’ll do so. Otherwise they’ll be just fine.
Waxleaf ligustrums. There were 30 years when these were the mainstay shrubs of North Texas landscapes. We’d grown tired of arborvitae and junipers, and we planted these across the fronts of a big percentage of our houses. Then the prolonged cold of Dec. ‘83 into Jan. ‘84 took them all out and you didn’t see them for a good while. December 23, 1989, forced a reset on the few that had been replanted. But we gradually started replanting them, and now we are back to small numbers. Their leaves have been toasted, and it’s quite possible that the plants will be hurt badly or killed. Willowleaf hollies are far better choices if we have to replace the waxleafs.
Several plants. Pittosporums, gardenias, fatsias, loquats, star jasmines and sweet viburnums: These are some of the prettiest plants in Texas landscaping, but the truth is, these plants aren’t reliable as far north as Fort Worth/Dallas. In fact, they’re risky north of College Station and Austin. They even froze in Houston and San Antonio this year.
Palms. We’ve gotten comfortable in using these around pools and patios, and they’ve done quite well for a number of years. Windmill palms and California fan palms are some of the hardier types, but even they were burned badly by the cold. Folks tried all measures of wrapping and covering, but in most cases it wasn’t enough to save the leaves. We’ll just have to wait to see if the growing tips have survived. That’s the critical issue. If so, new leaves will be produced once it gets warmer in April and May. For now, all we can do is trim off the dead leaves and wait.
Perennials. Most perennials are more common in the North and Midwest, so they’re well suited to cold. Early types like daffodils that were starting to bloom are done for this year, but hopefully they’ll have enough stored reserves to come back anew in 2022. Most of the rest should get a good start as the soil warms and spring settles in for good. Only the tropical types like Gold Star Esperanza, Mexican bush salvia, trailing lantanas and perhaps also bananas are likely to be lost.
St. Augustine lawns. Some of us were here gardening after the extremely cold night of December 23, 1989, when we hit temperatures as cold as last week’s. We remember the massive damage that was done to St. Augustine that year. We’re hoping the snow pack protected our lawns this time around. We won’t know until late March and April.