Perform This Test on Your Damaged Landscaping To See If It’s Dead or Dormant

North Texas lawns and landscaping will be paying the price for last week’s extreme winter weather long after the temperature rises. The landscape experts at Lawns of Dallas say we won’t know the extent of winter weather damage until at least spring.

“Don’t do anything hasty with your plants right now,” says Ryan Burrow of Lawns of Dallas.

Though your landscaping may look dry, wilted, or dead, don’t pluck them out of the ground yet. “They might just make it,” he says.

The Scratch Test

In a video Burrow posted to Lawns of Dallas’ Instagram, he shows the effects of frost damage on Ligustrum or Privet plants, a favorite evergreen shrub throughout Texas.

He suggests a scratch test to know if a shrub is dead or just dormant. To perform the scratch test, start near the tip of a branch or stem and use your fingernail to remove a small section of the stem’s bark-like surface.

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If it’s bright green, it’s alive. If it’s dull green, that indicates your plant is alive but in poor health. “They’re going to make it, but they’re not going to look great for the next few months,” Burrow says.

If it’s brown, black, or gray, that branch is dead, but try testing other branches to see if the rest of the plant is alive.

“At first glance, they may look like goners, but scratching their stem reveals ‘live’ green tissue,”

Plant Prognosis

All plants have a critical temperature point, a temperature at which physiological frost or freeze damage occurs. Tropical plants such as palm trees have a higher critical temperature point whereas plants more acclimated for colder climates can survive lower, even below-freezing temperatures.

“The length of time in those critical temperatures is important,” Burrow says.

“Critically low temperatures can cut a plant’s lifespan in half.”

Shrubs on the northern side of your home or building are more likely to perish since they were shielded from the ice-melting sun the longest, Burrow says.

Young plantings are also very vulnerable right now. “If they’ve been in the ground less than a year, they may not survive,” Burrow says.

Unfortunately, that means the young tree you planted to replace the one you lost in the 2019 North Texas tornadoes may be vulnerable as well.

Most Vulnerable Plants

Lawns of Dallas team members have been doing walkthroughs with customers looking for plant loss and damaged irrigation in the past week. They’ve seen the most extensive losses in these types of plants:

• Ligustrum (Privet, Sunshine Ligustrum)
• Pittosporum (Mock Orange)
• Loropetalum (Fringe Flower)
• Buxus japonica (Boxwoods)
• Trachycarpus (Windmill Palms)
• Cycus revoluta (Sago Palms)
• Washingtonia (Mexican Fan Palms)
• Ficus pumila (Creeping Fig Vine)
• Taxus (Yew, Podocarpus)
• Many flowering shrubs with soft leaves (i.e. Azalea, Hydrangea, Roses, etc.

What to Watch For

Windmill Palms or Mexican Fan Palm Trees: Though you might have wrapped the trunk of your tropical palm, the crown is most vulnerable. If the palm has a rotting crown, or you can easily pull fronds out of the trunk, it won’t likely bounce back.

Dwarf Palmetto or Sabal Minor Palm Trees: Of all tropical palms, this small species is most likely to survive the freeze. If the center bud is firm, it might survive by cutting away drooping or damaged leaves. Again, if the crown is soft or mushy, it’s not likely to survive.

Large Sago Palms: Technically, these aren’t palms, but rather cycads that can tolerate temperatures down to 15 degrees. But as Lawns of Dallas crews have seen, many Sagos with frost-damaged yellow leaves or soft trunks are likely to perish.

Shrubs and Wood-Stemmed Perennials: Perform the scratch test to see if they’re still alive. Cut away dead stems until you find green underbark. Don’t trim more than you have to because the threat of frost is not over. If you don’t find any green underbark, cut it back to near the ground and wait to see if it reemerges from the roots.

Succulents: Most succulents aren’t frostproof because they’re weathered for the other kind of extreme weather. As such, mushy, wilted cacti and agaves won’t likely survive after the prolonged deep freeze. However, there is hope if you have a firm center inside the collapsed outer leaves. Wait until warmer weather to prune them and see if they bounce back.

The lesson here is to learn to love ugly and be patient while plants try to survive. “Plants are like people,” Burrow says. “They have emergency responses to save themselves. They go dormant to concentrate on pulling nutrients from their roots and work hard to try to survive.”