WEST TEXAS - Three months after Winter Storm Uri blasted Texas with a week of freezing temperatures, many landowners are concerned the cold weather killed their oak trees.
Texas has a wide variety of native oak species, with many prized trees on private and public lands estimated to be hundreds or even thousands of years old. So, landowners were understandably alarmed when other species of trees budded out as normal while oaks remain bare-branched or sparsely leafed.
What likely happened instead is that the oak trees had already expended energy into producing new buds for this year’s growth, thanks to warmer-than-average temperatures throughout much of the winter.
When the artic weather arrived in late February, the liquid components of starches, sugar and water pulled from the roots to develop buds froze, effectively killing off new growth.
The dieback is not unusual and even expected during long, hard freezes. It just may have hit Texas’ oaks harder because they were already struggling, according to Gretchen Riley, TFS Urban and Community Forestry Program leader.
Now, TFS biologists and arborists in Central Texas are seeing a drastic increase in caterpillars. As stressed trees are more susceptible to disease pathogens and insect damage, many are losing what vegetation they had to the hungry insects.
It’s tempting to try different fertilizers or pesticide sprays to help the trees recover, but TFS advises landowners that a “wait and see” approach is the better course of action right now.
Unless the tree has been diagnosed with a specific nutrient deficiency, fertilization may do more harm than good. Indiscriminate fertilization can lead to growth spurts, but the trees need to focus energy into repair and defense, Blevins said.
While trees without any leaves on them by mid-July are likely dead, other trees may take a full year to recover from the winter storm. If oaks look sparse or sickly this year, it’s okay to wait until next spring to see what develops before making any final decisions.
Many of the oldest trees have survived decades or centuries without human interference so waiting is the best approach to saving stressed oaks.