Master Gardener: What to do with plants after a freeze
Published 12:43 am Saturday, February 20, 2021
Adapted from an article By Heather Kirk-Ballard LSU AgCenter Horticulturist
Now that we have had many days of freezing and below temperatures, many of us probably have lost some of our favorite plants even tho we had taken caution to protect them from the cold weather. I checked the soil temperature (Thursday morning 10 a.m.) and it is at 42 degrees F. Based on this, hopefully the soil did not get down to freezing on the bad days we had. As long as the soil did not freeze, most of the perennials, shrubs, etc. should be alright. They will look bad until they come back in the warmer weather of spring, but some may take longer to show any life as they will be coming back from the root stock and not the stems.
Next, you should understand the signs of freeze damage. The signs are pretty evident. Our plants will not look the same. Most tropical plants will lose turgidity, become droopy or shriveled and resemble a plant that is lacking water. Additionally, foliage will turn from green to brown or purple. Under an extended hard freeze, you may see plant stems splitting and peeling. I hate to say it, but if you see this, you’re likely burying that plant for the second time, and there will be no resurrection.
In extended hard freezes, the water in between and within the cells of the plants will freeze, causing the cells to expand and rupture and resulting in damaged plant tissue. This type of damage is typically irreversible. You will see this most often in tropical plants after a freeze. These include plants like hibiscus, cannas, pentas, vinca, angel’s trumpet, banana trees, gingers, succulents and cassia trees. Think leafy plants. Sadly, it’s typically those with the best flowers.
If you did get caught off guard and your plants suffered freeze damage, you can do some things to help them recover. The amount of damage depends on the severity and duration of the freezing temperatures. Since we had a long hard freeze, only time will tell.
After the freeze, you should be patient. Do not go straight for the pruners and cut everything back. It takes several days or weeks for plants to show us just how damaged they are. If plants are mushy and slimy, remove this material to prevent fungal infection or disease in the days to come. You may cut out the dead material to clean things up.
For woody plants, it’s best to wait until spring. Don’t get clipper happy and start cutting things back. You can check for life on woody plants and perennials by scratching the bark of stems and look for green color underneath. If you find green, you’re in luck. Your plant is still alive.
If you covered plants, remove the covers on warm, sunny days but keep them close by. It will likely freeze several times over the winter. Check your weather apps and watch the news periodically. If it is going to warm up for several days, plants that were moved into shelter can be moved back out. They will need plenty of sunlight to photosynthesize and stay healthy. Remember, plants make their own food from energy from the sun.
Caring for our plants during freezing weather is a labor of love and can be a great deal of good exercise. You can keep tropical and sub-tropical plants going year-round by taking the proper precautions. Or you can look at it on the bright side: Mother Nature takes care of pruning for us in winter. Tropicals and herbaceous perennials that have grown unruly over the summer got a good trimming. They may flush out again next spring, coming back from their roots.
If you have any gardening questions, please call our Hot-Line 409 882-7010 Tuesday and Thursday 10 a.m. – 2 p.m. Or you can visit our website https://txmg.org/orange and contact us via email at firstname.lastname@example.org.
Sheri Bethard, Texas Certified Master Gardener, Orange County Master Gardeners Association