We have had a number of customers asking about the damage to their plants after the recent holiday winter storm. We missed much of the snowfall however we did not avoid the wind and cold temperatures. Now the big question is the extent of damage and the next steps for our lawns and landscapes. As a recap of the weather, we saw a 40-degree plummet from the evening of the 22ndthrough the morning of the 23rd. This rapid drop in temperature was accompanied by gusty winds and sustained temperatures below 15 degrees Fahrenheit for at least 32 hours and temperatures did rise above 32 degrees for more than 80 hours.
Freeze damage in plants is largely the result of ice formation within the plant that punctures cell walls, and the temperatures were certainly severe enough for this to occur. The rapid temperature, drop meant plants were less able to prepare their internal defense measures to tolerate low-temperature stress, and then wind contributed to the desiccation (drying) of the injured plants.
Most warm-season turfgrasses, such as zoysiagrass and bermudagrass, had already transitioned into winter dormancy before this event, so signs of damage won’t appear until warmer weather in the spring. The injury to the cool-season turfgrasses is quite visible with leaves that are usually green now have brown, necrotic, tissue. Many conifers are now showing a golden or brown coloration, but we will not know the extent of the injury for a few more months. Low temperatures might have been especially harmful to zone 7 or 8 landscape plants, such as Acuba, Camellia, Distylium, Yaupon holly, Indian Hawthorn, Loropetalum, Fig, and more. Close inspection of boxwood and azalea may reveal the bark is split, cracked, or peeling from the trunk. Because this disrupts the plant’s ability to move water from the roots to the leaves, plants with this type of damage are not expected to recover quickly, if at all. Spring might reveal some woody species, such as crape myrtles could be killed to the ground. Warm-season grasses, tender perennials, and even borderline woody plants could have been killed. The rapid change in temperature, the magnitude of the drop, and the duration of lethal temperature exposure may end up being a knock-out combination. Only time will tell the full extent of the damage that this winter weather event has caused.
If you’re wondering what you can do now First, be patient! The best course of action right now is to actually do nothing. For herbaceous (non-woody) plants, those that are borderline for our area (hardy banana, calla, canna, and more), as well as plants that are often evergreen (hardy ferns, Heuchera, Lenten rose, and more), may have been killed to the ground. Leaving that now-dead above-ground tissue may provide a bit of insulation in the coming weeks for that plant’s survival. So, don’t do extensive cleanup or mowing. You don’t want to get carried away with pruning woody plants either. Please wait until plants leaf out or don’t leaf out in the spring. This will give you the best indication of what to prune. Be patient; plants like bigleaf hydrangea may not resume growth until as late as Mother’s Day and Flower buds except those that develop on new growth were likely damaged by the cold temperature. Plus, pruning now could expose still-living tissue to further cold damage in the coming weeks. Same with replacing plants let’s see what the plants do in the spring. As the effects become clear, we’ll either be relieved to see the return of old plant favorites, or we’ll get to select some exciting new plants for our lawns and landscapes.
Advanced Lawn Solutions Team