In the week after Winter Storm Uri, one of our state horticulture specialists commented that we would be answering freeze damage questions for the next year. He was right! We are nearly six months post-freeze, and I answer freeze related questions daily.
The top two concerns that I hear about are trees that only have shoots coming out on the trunk and main branches and trees that have big cracks on the trunk. The Texas A&M Forest Service released a great article this week to help homeowners determine if a tree is worth saving.
The summer heat is the true test of which trees survived the freeze. Many trees have leafed out this summer and look healthy. Some have a thinner canopy, but we expect them to look even better next year. Trees with at least 50% or more of their normal canopy are likely to survive and continue to improve.
I have seen a lot of trees this summer that are almost poodle-like in appearance. They have a bushy growth of shoots and leaves on the trunk, but very few or no leaves in the canopy. By this point in the summer, that is a cause for concern.
The Forest Service has a handy method to determine if your tree might make it. Imagine drawing a big circle around your tree’s branches and limbs. If more than 25% of that circle is filled with leaves, there is a chance for recovery. If not, the tree is likely going to die. Most of us want to hold out hope for our trees, and that is okay! I recommend taking a picture of the whole tree now, and then take another picture of the tree in the same spot next spring. If the tree has more leaves in the spring, you can rest assured that it is making a comeback.
The second concern are the cracks developing in the trunks of oak trees. These cracks occurred during the freeze when the water inside the tree froze and expanded. The outer layer and bark of the tree was not able to expand, which caused ruptures and cracks in the trunk and bark. Frost cracks like this are called “radial shakes.” We were not able to see many of these cracks until the summer heat came along and made them look worse.
Fortunately, trees are very good at sealing over trunk damage and cracks. One or two cracks in the trunk of a tree is not a major cause for concern. If you have multiple cracks or a lot of exposed wood, monitor the tree for insects and browning foliage. Lacebark elms, sycamores, and crape myrtles will shed bark as part of their natural process, so do not be alarmed when you see that happen.
For more information about lawn and garden topics, contact Kate Whitney, Williamson County Extension Horticulturalist, at 512-943-3300.
Photo from Texas A&M Forest Service.
