I know I’m not the only sad homeowner seeing my once flourishing shrubs looking brown and crunchy after the big deep freeze earlier this month.
I wondered if all is lost because of the subzero temps — or if there could be any hope for them to come back to life in the months to come.
So, I contacted expert Amy Dunlap, the Davidson County Extension Agent, to inquire about the impact of the latest flash freeze and found that I was not the only one concerned about our landscaping.
“Extension offices have been inundated with inquiries regarding the recent freeze,” Dunlap said. “Some people don’t necessarily attribute their plant’s damage to the freeze, so I’ve also gotten a lot of questions asking about disease when it is in fact freeze damage. In the last week I probably received 40-50 calls and emails.”
Dunlap stressed that the best path forward is to be patient and to not rush to prune until spring when you can see the full extent of the damage.
“It’s likely the full extent of damage will not become apparent until spring. If stems are not damaged, the plant has a good chance of surviving,” she said. But “It may take a season or more for plants to fully recover.
“It’s best to monitor plants and wait to prune out dead or severely damaged foliage/branches until at least the end of February to avoid further freeze damage to open pruning wounds. Corrective pruning should not be started until the full extent of the damage can be determined.”
She said, “If you are concerned about whether a plant is still alive, you can always perform a ‘scratch test.’ This can be done by gently removing (scratching off) a small section of the bark on small stems/twigs to expose the cambium. Green tissue indicates a living stem. If the tissue is brown, then it is dead. Keep in mind that different plant tissues (leaves, buds, stems) on the same plant can vary in cold hardiness.”
“Unfortunately, many plants in Davidson County suffered damage due to the rapid drop in temperature experienced during the freeze,” Dunlap said, adding that laurels were particularly negatively impacted. “This can be due to several single causes such as low temperatures, sudden drops in temperature, high winds, etc. Or it may be due to a combination of them.”
She explained that “damage caused by the recent freeze was not due to the cold itself, but the extreme and rapid drop in temperature we experienced. Normally as the temperature goes down plants draw more water into their roots. This helps keep ice crystals from forming inside the plant cells. But in a flash freeze, plants don’t have time to react. The water inside the cells freezes, crystalizes, and begins pushing out (water expands as it freezes) puncturing the cell walls as they go. Cell damage = tissue damage. Tissue damage = plant damage (TDA).”
She went on to say that “All leaves lose water or transpire through their leaves. In the fall deciduous plants drop their leaves as they stop growth and this materially reduces transpiration. Evergreens, however, retain their leaves throughout the winter and therefore continue to lose water through them.
“This water loss is greater when winds are high and when the sun is bright and warm. The roots continue to absorb soil moisture as long as it’s available, but if it is not available, either because of a serious drought or because the ground is frozen, then trouble starts.
“Water continues to be given off through the leaves and when no more is taken up by roots to compensate for that lost through the leaves, some is taken from the actual living cells. When too much is lost this way, the cells die, with the resultant browning or death of the evergreen foliage,” Dunlap said.
Dunlap says Middle Tennesseans will also likely see damage in deciduous trees/shrubs when they try to leaf out in spring. And she said that recently planted or young plants are particularly vulnerable and may have been killed by the flash freeze damage.
Dunlap said it is hard to estimate the economic impact of the freeze – “I don’t have an estimate on economic damage. We probably won’t have an accurate idea until we come into spring, and we can assess damage to deciduous trees as well that may not be displaying signs of injury yet. It’s also difficult to say right now what was killed and what will eventually rebound. We are recommending a wait and see approach.”
She also said that if you want to protect your plants moving forward, to check out extension.uga.edu/publications “Most winter protection is aimed at reducing water loss from foliage. As damage cannot be reversed, it’s best to focus on keeping them as healthy as possible,” she said.
We should all hope for the best!
Mary Hance, who has four decades of journalism experience in the Nashville area, writes a weekly Ms. Cheap column. She also appears on Thursdays on Talk of the Town on NewsChannel5. Reach her at mscheap@mainstreetmediatn.com and follow her on Facebook as Facebook.com/mscheap
