Tag freeze-thaw cracks

Are Trees Still Showing Signs of Freeze Damage? [May 2022 UPDATE]

by Texas Tree Surgeons Extreme Weather, Resources, Tree Health Care

Unfortunately for trees in North Texas, the effects of the February 2021 winter storm, often called “Winter Storm Uri” in the media, are still with us. The historically-low temperatures and winter precipitation in 2021 and the winter weather in February 2022 had a devastating impact on the health of trees and other vegetation and  recovery from those extreme conditions will take time. Common landscape trees in the DFW area, such as ash, live oaks, red oaks, wax myrtles, chinaberries, and Chinese tallow trees were some of the worst damaged by the freezing conditions and so the damage can still be seen in many parts of our community.

Different species and types of trees responded differently to the low temperatures.
Visit our previous posts for specific info:

My Tree Leafed Out in Spring 2022 but is Now Turning Brown. Is That Freeze Damage?

Due to the unprecedented nature of the winter weather in 2021 and 2022, it has been difficult to predict exactly how trees will respond and the nature and timing of any freeze-related decline.

  • Some species have seemed to bounce back from freeze damage only to show browning and die back after two or more growing seasons.

    • Red oaks and Japanese maples have been observed to leaf out in the spring as normal, only to start browning a few weeks later.

    • Unfortunately, once a tree’s canopy has completely browned or died, the tree may not be salvageable.

  • If a tree has partial browning or only some dead canopy:

    • Prune out the dead or dying sections

    • Follow good watering practices

    • Use soil amendments focused on increasing available nutrients

      • High nitrogen fertilizer is NOT recommended, as this can stimulate the tree to use up energy reserves to push new growth rather than increase overall health

A tree exhibiting severe freeze-thaw cracks. Even less drastic cracking can reduce a tree’s defenses against pests.

Should I Be Worried About Cracks in the Bark of My Trees?

Freeze-thaw cracks occur when rapid temperature swings cause the wood of a tree to swell and contract faster than normal. These cracks vary in size and severity. When the water inside a tree freezes, it can damage the tree’s vascular system, which moves nutrients throughout the entire tree. Widespread damage to the vascular system can lead to tree death.

Trees with freeze-thaw cracks need special care to encourage vascular system growth and nutrient availability.

  • Proper watering is essential.

  • Soil amendments and low nitrogen fertilizers can make additional nutrients readily accessible to the tree’s roots.

    • Fertilizing stressed and damaged trees must be done with care.

    • High nitrogen growth stimulators should be avoided.

  • Preventive insect treatment is recommended.

    • Cracks or other wounds in the bark are entry points for borer beetles and other pests.

    • Over time, the tree will be able to seal off (“compartmentalize”) the damaged sections, but this can be a slow process.

Why Does My Tree Have Large Dead Branches?

In cases where only parts of a tree were subject to severe frost damage, the main trunk may be free of freeze-thaw cracks or other issues while some large or small sections of the tree show browning and dieback. With rapid temperature swings and violent winter weather, a tree’s specific location and surroundings (such as nearby structures or other trees) can have a great impact on how the tree is affected. Because of this, trees of the same species on the same block may have shown wildly different responses to freezing weather. No matter the extent, it is best to remove dead and dying sections of the canopy and bolster the tree’s health with water and nutrients to give it the best chance to compartmentalize the dead and decayed sections and return to health.

At Texas Tree Surgeons, we love trees and we love our community! Recent extreme weather events present new challenges to our urban forest and it will likely be a few years before we have seen the full effects. Trees, by their nature, respond slowly to environmental changes and, if not properly cared for, can slide into a cycle of decline following storm damage or other severe weather. As we move into the heat of the summer our current drought conditions can worsen and accelerate tree decline and dieback. Now is the time to have one of our arborists evaluate your trees for their current needs and prescribe a health care plan to increase soil nutrient levels and manage insect activity. Contact us today!

Will My Trees Survive Freezing Temps and Winter Weather?

by Texas Tree Surgeons Extreme Weather, Resources

The effects of the historic freezing temperatures in February 2021 are widespread. After the ice thawed and the snow melted, many people were left with frost-damaged or dead landscaping. While much of the damage from the rapidly-changing temperatures is obvious, trees and plants have also suffered internal damage, and will likely show signs for years to come.

Will the freezing temperatures and winter weather kill my trees?

Unfortunately, we can already see the signs of frost-killed plants: leaves and other plant tissue that appears wet, soft, brown/black, or dried up. This type of damage is prevalent in succulents, pittosporum, loropetalum, geraniums, and related plants. Palms will likely also suffer extensive frost damage, but it is best to wait until the summer to see if they put out new growth. 

Evergreens and more frost-resistant trees and shrubs should fare better. Common examples of this group of plants are yaupon hollies, wax myrtles, and crape myrtles. These species may brown in sections, but ultimately survive. Even if they survive, some of the brown sections will never recover. It is best to wait until summer for new growth to see the extent of the damage. 

Trees with thinner bark, such as fruit trees and Japanese maples, may leaf out in the spring and appear unharmed. Damage to the inner layers of the tree, however, can prevent proper movement of water and nutrients in the tree’s vascular system and can lead to stress symptoms in the summer, appearing as a sudden browning and wilting of the leaves. 

Larger native trees such as red oak and pecan may show dieback or brown sections, but should recover if cared for properly. Live oaks may show browning, but should recover and put out new leaves in spring.

Frost Cracks

Frost cracks are caused not by surface frost, but by fluctuating temperatures, and are most-often seen on the southern sides of trees, which get more direct sunlight. On a cold but sunny day, the sun warms the exposed areas of the tree, causing expansion. When temperatures drop rapidly at night, the bark cools and shrinks faster than the tissue underneath. As the bark shrinks, it splits vertically over areas where the underlying wood is still expanded. Splitting and cracking is most common in areas where there are wounds or other damage that has weakened the bark. Young trees and trees with thin bark are especially susceptible. Frost cracks are rarely fatal and will heal over time, but can be entryways for disease and insects. Stressed trees exhibiting cracks should be given special attention and should be properly fertilized and cared-for to help protect against diseases and insect activity.

CAN I DO ANYTHING TO HELP MY TREES RECOVER FROM THE FREEZING WEATHER?

 For freeze-damaged plants, it is important to provide proper care in the short and long term. 

 WHAT YOU SHOULD DO NOW: WAIT!

  • Watch for signs of damage.
    • Browning and widespread leaf drop will be common.
    • Wait until spring or summer before deciding if a plant is salvageable.
  • Water correctly.
    • Once the ground has thawed out, and temperatures are consistently above freezing, do a deep soak watering for the roots of trees.
      • Use a hose, not sprinklers.
    • Watering can help a tree with damaged leaves to take up nutrients. 

WHAT YOU SHOULD DO IN THE SPRING

  • Have frost-damaged trees evaluated by an local ISA Certified Arborist.
    • Every tree species will react differently to the freeze.
    • Factors like location, soil conditions, and even the movement of the storm front will affect the trees’ ability to survive.

WHAT YOU SHOULD DO OVER THE NEXT FIVE TO SEVEN YEARS

  • Fertilization and proper watering will be key to freeze-damaged trees.
    • Nutrient-rich soil with beneficial bacteria and fungi can speed a tree’s recovery.
  • Do not use herbicides around affected plants.
    • Never use a “weed and feed” product near your trees.
  • Continue proper maintenance trimming and care.
    • Remove dead wood and loose bark, thin for light and air.

At Texas Tree Surgeons, we love trees and we love our community! The freezing weather in February 2021 caused damage not just to North Texas’s infrastructure, leaving many without power, water, and shelter, but also to our urban forest. Once the needs of our residents have been met, it’s a good time to think about how best to care for our frost-damaged trees and shrubs. We are here to help you evaluate the damage to your landscaping and make an informed decision about how to proceed. If your trees and shrubs don’t leaf out in the spring, or you have any other questions, let us know! We have a team of ISA Certified Arborists ready to help in any way we can!