Archives May 2022

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!

How To Care For Trees During a Drought

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

With over 90% of Texas in drought conditions, water conservation measures are in effect over much of the state. Caring for our urban forest during a drought requires special attention to our watering practices to ensure that trees get the water they need and none is wasted.

Do I Really Need To Water My Trees? I Have a Sprinkler System!

Yes! Even if you have a sprinkler system or regularly water your lawn, you need to water your trees as well.

  • In-ground irrigation systems and hose-attached sprinklers are designed to provide water for turf grass and other ground cover.

    • Some sprinklers may be able to provide more water for small shrubs and bushes, but none of them are adequate to meet a mature tree’s water needs.

  • If a tree is not properly mulched, it may be in competition for water resources with other plants.

    • If there is artificial grass present, water and nutrients in the soil may be scarce.

  • Without adequate water, trees’ immune systems weaken, leading to increased susceptibility to disease and insects.

    • Repeated, long-term stress from lack of water can lead to a cycle of decline and tree death.

What is the Best Way to Water My Trees?

There are two main ways to get sufficient water to your trees: using a soaker hose or hand watering.

  • Soaker Hose

    • Recommended for ease of use and coverage

    • Make sure the hose can cover the entire root zone

      • Depending on the type, hoses can be arranged in circles or a spiral around the tree or in radial lines leading out from the trunk

    • Run the soaker hose long enough to wet the ground in the root area to a depth of 10-12 inches

    • Check the soil to see how long it retains moisture and only water after the soil has dried

      • Too much water can be as bad as too little

      • Generally, watering should be every 7-10 days

  • Hand Watering

    • Place a garden hose so that the outlet is 1-2 feet from the root flare of the tree

    • Turn on water enough to spread, but not so much that it puddles or streams away

    • Move hose around tree to ensure even watering of entire canopy area

    • As with soaker hoses, stop watering when soil is damp to a depth of 10-12 inches

    • Wait a few days and check soil moisture

      • Re-water when soil is dry to avoid excess dampness

  • Special Considerations

    • Some trees may require watering more often

      • Stressed/sick trees (such as by freeze damage or pest activity)

      • Non-native species

      • Recently-planted trees

    • During periods of wet weather, do not water too often

      • Excess soil moisture can cause rapid growth of harmful microorganisms

How Can I Help My Trees Retain Moisture in a Drought?

After watering, mulching is the most effective way to regulate tree moisture. Proper mulching helps regulate soil temperature, slows evaporation, and contributes to soil nutrients as it breaks down.

Avoid high nitrogen fertilizers and growth stimulators, as these can cause a tree to use up energy stores and require more water to maintain. Organic soil amendments and compost can be added to soil and mulch if needed.

At Texas Tree Surgeons, we love trees and we love our community! While the summer months can be fun, the drought conditions they often bring can be stressful to people and plants. Proper watering of our urban forest leads to healthy trees that can help regulate heat, provide shade, and keep the air fresh. Have questions about how best to care for your trees during drought? Contact us today!

Emerald Ash Borer in North Texas 2022 Update

by Texas Tree Surgeons Resources, Tree Health Care

As previously reported, the emerald ash borer beetle (EAB) has been making its way into North Texas in recent years. In 2016, specimens were found in Harrison County, Texas, near the Louisiana border. By 2018, the beetle had spread to Tarrant County. By 2022, EAB had been confirmed to be present in eight Texas counties: Bowie, Cass, Dallas, Denton, Harrison, Marion, and Tarrant. These areas are now under a Texas Department of Agriculture quarantine that restricts the movement of ash trees and tree materials, as well as firewood from all hardwood species, unless properly handled or treated.

While not the most common tree in our North Texas urban forest, ash species do make up 5-13% of the trees in the DFW area. While EAB poses a serious threat to the health of ash trees, there are preventative measures that can help slow the spread of the beetle and protect unaffected trees.

How Do I Tell If I Have Ash Trees?

Ash tree identification can be a little tricky if you are not used to it. Many North Texas can easily spot the distinctive leaf shapes of many oaks or maples, but the leaves of ash trees may cause them to be identified as pecans or other trees with similar leaf structures. One distinctive feature of ash trees is the seed pods that appear in the fall, and can be seen spiraling down as they drop to the ground.

  • There are several types of ash tree seen in North Texas; most commonly:

    • Arizona ash (Fraxinus velutina or Fraxinus berlandieria)

    • Green/red ash (Fraxinus pennsylvanica)

    • Texas ash (Fraxinus albicans Buckley or Fraxinus texensis)

  • All ash varieties have similar characteristics:

  • Compound leaves

  • Tan to gray fissured bark

  • Unique seed pods

If you are unsure about what kind of trees you have, contact a local certified arborist who can help with identification.

What Should I Do about EAB If I Have Ash Trees?

With the spread of the emerald ash borer beetle, ash tree owners need to be particularly mindful of the state of their trees.

  • Preventative insecticide treatment can be effective

    • Must be administered before EAB is present

  • Diseased or damaged ash trees should be removed

    • EAB is attracted to the dead/dying wood and points of decay

  • Watch for signs of EAB

    • Dieback in upper canopy

    • Shoots/suckers along branches

    • Splitting/shedding bark with insect trails (“galleries”) underneath

    • Increased woodpecker activity

    • D-shaped holes in or under bark

  • EAB-infested trees

    • Once EAB is present, little can be done

      • Insecticide can slow decline in some cases

      • If more than 50% of canopy is dead, treatments are not effective

    • EAB kills trees in 2-5 years

EAB and Freeze-Damaged Trees

Trees in North Texas have been stressed by the freezing weather in recent years and are therefore more susceptible to pests of all kinds, including EAB. Dead branches in the crown of a tree may be a holdover from freeze damage or may be a sign of an infestation. Proper after-freeze care can help a tree regain its health and vigor, but any stressed ash trees should be assessed by an ISA Certified Arborist to ensure that EAB is not present. Preventive systemic insecticides are strongly recommended for stressed ash trees.

The tree on the right was treated with preventative EAB pesticide. The tree on the left was not treated due to frost damage. Both were exposed to EAB.

At Texas Tree Surgeons, we love trees and we love our community! The continuing spread of emerald ash borer in North Texas is a serious threat to our urban forest. Our arborists are staying up-to-date with guidance from the Texas A&M Forest Service and the Texas Department of Agriculture to provide the highest level of care to our customers. If you have ash trees, even if they look healthy, give us a call to discuss whether preventative treatment is recommended for your area. If you have sick or stressed trees of any species, we offer full-service plant health care programs and can give your trees the best chance to survive and thrive. Get in touch today!