Freeze Damage Fallout

by Troy B. Marden

The following sage advice on freeze damage was written by Nashville Public Television’s Volunteer Gardener Troy B. Marden following the Christmas 2022 actic blast.

Many friends are beginning to post photos of damage to plants, like these Aucuba in my garden, from this weekend's record cold. The real problem for most plants was not the cold itself, but the extreme and rapid drop in temperature. At my house, it dropped from 53 degrees at 3 p.m. to 0 degrees at 3 a.m. When this happens, plants--and especially broadleaf evergreens-- don't have time to react. Normally, they would draw more water down into their roots, increase the concentration of sugars in their leaves (antifreeze for evergreens), or both. This helps to keep ice crystals from forming inside of plant cells.

In a flash freeze like we experienced this week, the plants don't have time to react and the water inside the cells of the plants freezes. Ice crystals are pointed and sharp and, since water expands as it freezes, push outward puncturing the cell walls as they go. Enough cell damage = tissue damage. Enough tissue damage = plant damage/death (sometimes partial, sometimes total, depending on the plant and the situation). Leaves usually take the brunt of the damage, but in some plants, stems may also be damaged. This damage usually takes longer to show up; sometimes months.

The key, now, is patience. Do not prune. Wait. The full extent of this damage is not going to be known until spring, and maybe beyond. If the stems have not been damaged, many plants will leaf back out. Even so, it may take a full season or two for some plants to recover.

We will also see damage in deciduous trees and shrubs. You can count on it. Thin-barked species like crape myrtles, Japanese maples, and others may have suffered damage that will be completely hidden until they try to leaf out in spring. Small stems, less than 3/4" or so in diameter may have been killed outright in more tender species. You may also see bark damage in the form of splits or cracks running up the stems/trunks, or dead patches of bark (which usually turns black). Depending on the extent and location of this damage, you may see the death of some or all of the stems or, in the worst case, tree trunks and the resulting death of the tree.

In a similar situation in Tennessee in the late 80's, mature 'Nellie R. Stevens' hollies (and many other species, both native and non), crape myrtle, etc. were killed completely to the ground. Don't be surprised if it happens again, especially on recently planted and/or younger and less-established plants.

Tennessee Home Fruit and Vegetable Garden

2023 Calendar

The Tennessee Home Fruit and Vegetable Garden calendar has been developed to assist you in formulating an overall plan for your residential vegetable garden and fruit production. Utilize the calendar to schedule various planting, harvesting, and management practices. However, there are many other excellent resources available from UT Extension that will be an asset to you in planning and managing your garden, so they are linked within this calendar. We hope this calendar is one step in your successful home fruit and vegetable journey.

Click on the image of the calendar's cover to download your own PDF version for free!

Tennessee Extension Master Gardener Program to Begin Again in January

by Bob Ary, Robertson County Master Gardener Coordinator

This article originally appeared in the December 2022 issue of The Leaflet.

The objectives of the Master Gardener program include:

1) To increase participant knowledge of horticulture, and

2) To encourage the sharing of horticulture knowledge with others through education and volunteering.

Becoming a Tennessee Extension Master Gardener in Robertson County requires the completion of approximately 40 hours of training followed by 40 hours of volunteering and an additional 8 hours of continuing education as outlined and approved by the Extension Agent/Advisor, hopefully within one year of completing the training. You will receive your Tennessee Master Gardener Handbook and other training materials during the training. Master Gardeners are also active helping others through individual and community projects.

Training will be conducted using a hybrid format in a face-to-face group meeting with statewide virtual instruction using Zoom or similar program. Training sessions will be on Tuesdays beginning at 9:00 am in Springfield (exact location to be determined) on January 31. Sessions will conclude by noon. Other training sessions may be conducted locally as needed to complete training requirements, dates to be determined and may include Saturdays.

Internet service is a must, as you will access online educational materials, video segments, etc. prior to/after the educational sessions.

The registration fee is $150 for individuals or $200 for two members of the same household sharing training materials.

For those who are new to Tennessee, this is a great opportunity to learn more about gardening in Tennessee, meet others who share an interest in gardening, and to become engaged in the community through volunteering.

For more information related to the training, or to receive a tentative class schedule, please email bobary@utk.edu.