How to aid oak tree survival after the big 2021 freeze
ANGELINA COUNTY, Texas (KTRE) - It has been asked again and again, yet the question remains: “Was my oak killed by this past February’s awful freeze?”
Of course, it bears repeating, “We don’t know. We may still need to wait before making that call.”
Let us break this into three visual categories: fully leafed-out, pockets of leaves throughout the tree, and absolutely no leaves.
For those trees that appear fully leafed-out, we have no worries at all. For whatever reason, the tree is in excellent condition and needs no attention. This applies to the majority of oaks and other trees.
For those that are partially leafed out, we need to watch these closely. Partially leafed out could mean that you see scattered green leaves throughout the canopy or maybe “pockets” of fully developed leaves. Most experts have high hopes for these trees and expect them to fully recover later this year if not the next year. Give oaks in this category a reprieve from the chainsaw until at least spring of 2022.
The last grouping are those oaks that have no leaf emergence at all and even have bark falling off or dead limbs falling off. Being optimistic, I still may give them a month or two. But you may need to consider the cost of removing it from your landscape so that injury to property will not occur from falling limbs.
On my own property, I have four large oaks that have not fully leafed-out this spring. Of those four around my home, I know that one is certainly dead. It has bark falling off and every indication of hypoxylon canker. The other three show signs of recovery. If you study them, you will notice the emergence of a few leaves.
Generally speaking, there are several factors that impacted the survival of some landscape plants. First was the exposure. Lone, isolated trees took the brunt of wind and cold, and certainly had a more difficult time. A lone tree on the north side of your house got a tougher dose of cold injury that the group of trees huddled together on the south side.
Low lying areas is where the coldest air always settles. Looking around a neighborhood or your property, you may see plant survival rates differ due to simple changes in elevation.
Dry soils may have been a factor in the death rate of trees in some areas of the state. Dry soils with moisture stressed trees fared poorer than those who had adequate soil moisture.
Believe it or not, the snow had an insulating effect on the roots. The snow that preceded the bitter-cold temperatures coated the ground with a “blanket” that kept soil temps and those shallow roots from seeing the single digit temperatures that were just above the snow.
Planning ahead, one cannot help but reflect upon the USDA Cold Hardiness map that lists most of Angelina County in Zone 8b. If you live in zone 8b, history indicates that we should only reach 15 to 20 degrees Fahrenheit each winter. I still believe we should apply this guideline when choosing trees.
I know the questions will not stop. Yet, as we continue the watch and wait regimen with our oaks, the worst-case scenario is that you prepare yourself for an abundance of firewood for the next winter storm.
Cary Sims is the County Extension Agent for agriculture and natural resources for Angelina County. His email address is firstname.lastname@example.org.
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