Tag oak wilt

Oak wilt

Common Tree Issues to Look Out for

by Texas Tree Surgeons Tree Owner's Guide

To keep your trees healthy it is recommended to have your tree assessed by an ISA Certified Arborist every year. They are able to spot issues that a homeowner may miss. Below are some common issues to intercept before they become costly problems for your trees.

Structural

Trees may have natural structural issues or may develop them in response to stress or other factors. Aside from breaking and falling limbs, trees can also develop instabilities in the root system.

Physical damage

Everything from nearby landscape maintenance to reckless driving can be a source of physical damage to a tree. Generally, the more damage is done to the bark and the layers just underneath it, the more impact damage will have on a tree’s health.

While trees cannot “heal” in the same way that animals can, there are ways that trees respond to wounds and can minimize the internal damage. A tree’s wound response does not usually need human intervention, and applying wraps or compounds is not usually necessary or advised.

Weather/Environment

North Texas is known for unpredictable, and often severe, weather. Storms, droughts, freezes, and high winds are just a few of the weather events we are used to. Properly preparing trees for the weather, and dealing with the effects of severe events is an important part of caring for trees.

Insects/Pests

Depending on the species, age, and location of a tree, it may be a target for many different insects, arachnids, and other pests. Some that are comon in North Texas are:

Diseases/fungi

As with pests, a tree’s susceptibility to disease depends on several factors. Some of the common North Texas tree diesases are:

Cycle of decline

No matter the particular type, all trees suffer from stress, pest activity, and potential for diseases. The factors contributing to a tree’s ability to recover from stress, damage, or infection range from the weather at a given moment to the genetic makeup of the particular tree.

Trees with certain underlying predispositions may react very differently to stress when compared to trees without those underlying factors.

Trees that have suffered recent damage may be less able to fight off an infection.

When considering the health of a tree, it is important to keep in mind the “cycle of decline,” the recurrent effect of internal and external factors have on a tree’s ability to maintain vigor and health.

Physical damage or poor soil conditions do not only have an immediate effect on a tree’s health, but factor in whenever a new stressor presents itself.

Failure to address these factors can hasten tree decline and death.

Additional Resources

The International Society of Arboriculture has guide of Tree Hazards

At Texas Tree Surgeons, we love trees and we love our community! We hope this blog on common tree issues will help prevent tree failure. We have additional resources on our North Texas Tree Owner’s Guide. If you would like immediate assistance with your trees please contact us today.

North Texas Tree Owner’s Guide

Water Your Trees Now!

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

Why should I water my trees in the winter?

After the extreme weather events in recent years, trees in North Texas are having a rough time.

  • Currently, 86% of Texas is under drought conditions, while North Texas is suffering from “severe drought”
    • Lack of water leads to a weakened immune systems in trees and higher susceptibility to disease and insects
  • Repeated, long-term stress can lead to tree decline
    • To avoid this, trees need extra attention and care NOW
  • While DFW-area trees are normally dormant during this time of year, warm temperatures have caused some to start budding out early, before the recent freeze
    • Producing new buds and leaves is a significant drain or a trees energy and water reserves

How should I water my trees?

  • Trees have different water needs than other landscape plants and turf grass
    Sprinkler systems are not sufficient for watering trees

    • Using the “slow soak” method every 7-10 days is best
  • A soaker hose around the entire root zone of the tree is recommended
  • If using a garden hose:
    • Place the hose 1-2 feet from the root flare
    • Run water at a volume enough to spread, but not so much as to puddle or stream away
    • Move hose throughout entire canopy area, ensuring complete coverage
    • Remember to let the ground dry between waterings to avoid over-watering
  • Non-native species, newly-planted trees, or stressed/sick trees may need watering more often
  • For more watering info, visit our watering guide or this publication from the Texas A&M Forest Service

What else can I do to help my trees during drought?

Mulch!

  • After watering, mulching is the most beneficial treatment for all trees
    • Mulch helps regulate soil temperature and moisture, prevents competition in the root zone, and adds beneficial nutrients to the soil
    • To learn how to properly apply mulch to your trees, visit our mulching guide
  • Remove any dead or damaged branches before spring
    • Dead wood is a magnet for insects and disease, and can become sites of rot and infestation
    • Branches that are dead or dying present a hazard, as they are prone to falling during inclement weather

Oak Wilt Season is Almost Here!

Oak wilt is a devastating disease that affects all species of oak trees. Spread through root systems and pruning cuts, the insects and fungi that cause oak wilt infections are most active between February and July every year. As always, we recommend avoiding all oak trimming, except for removing dead or damaged branches, during oak wilt season. If oak trees need to be trimmed during this time, we follow recommended protocols such as painting the cuts, which adds a fee of 20% to trimming prices. For more info about oak wilt, visit our post on the topic.

REMEMBER: Anyone who says that oak wilt is not a serious concern is incorrect. There is no known proven cure for oak wilt, and oak wilt treatments are expensive and do not have a high success rate. Prevention is the best approach!

Why Is My Tree Losing Its Leaves in Spring? [UPDATED]

by Texas Tree Surgeons Ask Texas Tree Surgeons, Resources, Tree Health Care

UPDATE: Was your Live Oak damaged by frost and freezing temperatures? Read our post here!

Why is my live oak looking sick and dropping leaves?

Falling leaves, just like color changes, have become a hallmark of Autumn, but not all trees drop their leaves in the Fall. In North Texas, we have a lot of live oaks, which is one particular exception to the “trees just lose leaves in Fall” rule. Are your Texas live oaks looking brown or sick and dropping leaves? It’s probably just a seasonal leaf exchange.

Live Oaks Have a Leaf Exchange in Spring

  • For many trees, dropping leaves is a way of preparing to go dormant during the cold winter months.
    • Live oaks, however, can lose leaves throughout the year and generally stay green during the winter. The major live oak leaf drop takes place in the Spring.
  • When the weather warms up, and the trees move out of winter dormancy, live oaks begin to develop new leaf buds.
    • Before the new leaves can grow, however, live oaks have to drop the old leaves.
    • As the old leaves die, they turn brown and fall, preparing for the new leaves to bud out.
  • If, however, the fallen leaves have yellow spots or yellow veins, there may be something else causing the live oaks stress.

At Texas Tree Surgeons, we love trees and we love our customers! If you’re new to the area, or just haven’t noticed before, seeing otherwise healthy live oaks turn brown and drop their leaves in the Spring can be a cause for concern, but don’t worry! Live oak leaf exchange in the Spring is part of the healthy life cycle of the trees, and is a sign that your live oaks are ready for new growth as the weather warms up. As always, if you have any questions about live oaks or any other trees, let us know!

Why Are My Oak Trees Turning Brown?

by Texas Tree Surgeons Ask Texas Tree Surgeons, Tree Health Care

As the summer heat drags on, we start to get calls about trees “looking bad.” Recently, for example, we have been seeing general decline of trees, especially oak trees, in the Plano area. In a densely-populated suburban area like Plano, there are many potential causes for trees showing signs of stress, displaying yellowing or browning leaves, or dropping limbs. While some issues may be symptoms of a disease, much of the oak decline we are seeing is, unfortunately, an inevitable result of the environment the trees live in.

Plano, Texas’ Urban Forest

Plano, Texas, is a great example of a community that loves its trees and values the beauty an urban forest can bring. As the city has matured, so have its trees, and many of them are now magnificent. However, when the community was planned and the trees were planted, developers depended heavily on different species of oaks: live oaks, red (Shumard) oaks, post oaks, and others. While these oaks are hardy, native Texas trees, any environment that is heavily populated by one species is susceptible to certain risks. The proliferation of oak wilt in North Texas is exacerbated by the heavy concentration of oaks in the area. Even without an outside stressor like the oak wilt fungus, any monoculture will slowly start to decline as competition for resources affects all members of a species, without the diversity necessary to replenish what was used.

The causes of oak decline in Plano run deep into the soil and deep into the history of the community. Before Collin County developed into the elegant mix of residential, commercial, and industrial areas that it is today, most of the land was used for farming and ranching. Agricultural land becomes exhausted of its nutrients after long periods of use. Moving from heavy agricultural use directly into construction doesn’t give the land time to recover. Heavy construction activity also leads to soil compaction, and if mixed fill is used, precious soil space is taken up by rocks, cement, and other inorganic material. Decades of growth and the spread of structures and concrete have further challenged the ability of Plano soils to renew themselves. Changing weather patterns in the last several years, periods of drought followed by flooding, have stressed the soil and plants even more. As turf grass has proliferated, much of the natural process that would introduce nutrients to the soil through decaying organic matter has been interrupted.

What Can I Do About Oak Decline?

While oak decline is an inevitability for many Plano oaks, the situation is not completely hopeless; there is much that tree owners can do to help restore their trees’ vitality:

  • Proper Mulching
  • Proper Watering
  • Reducing Competition
    • Turf grass, ground cover, concrete, and over planting of trees can all contribute to nutrient competition.

However, there are some issues that may be beyond remedy:

  • Poor Tree Stock
    • If the tree was sourced from a tree farm with weak stock, or with trees that had been exposed to pathogens before, it may have been at a disadvantage from the start. A plant health care program may be able to ameliorate some issues, but not all.
  • Improper Planting
    • Planting issues can be corrected if the tree has not been in the ground more than a few years. The tree can possibly be re-planted, or root zone excavation can be performed to identify other root stability issues, such as girdling roots. A certified arborist can determine if any corrective efforts are possible for your particular tree.

Contacting a certified arborist to assess your trees is necessary to properly identify oak decline and address the underlying issues, not just the symptoms. Insect activity may need more involved care than just spraying a surface insecticide. Browning or yellowing leaves may be a sign of many issues: fungal root infection, insect activity, or herbicidal poisoning, and don’t simply mean that you need to water more. A certified arborist is able to evaluate the tree and its surroundings as a whole, not simply one component. An effective tree health care program involves many components: care modification, fertilization, soil management, proper trimming, pesticidal application. To preserve the value of an urban forest like Plano’s, certified arborists are key.

At Texas Tree Surgeons, we love trees, and we love our customers, in Plano and all over North Texas. If you live in Plano, and want more information about oak decline and what may be affecting your trees, let us know! If you’re not in Plano, don’t worry! We are happy to come and take a look at your trees to evaluate their health and give you the information necessary to keep them thriving for years. As always, let us know if you have any questions or concerns about trees!

After the Storm…

by Texas Tree Surgeons Extreme Weather, Tree Health Care

Trees that survived the severe storm damage are going to need special care over the next few years. The loss of canopy will reduce the trees’ ability to photosynthesize for food and to take up water. We are entering the hottest part of the year; after the rains have passed, increased watering and fertilization are key. It is up to tree owners to supplement the nutrients that trees need, but can no longer absorb from their environment. Your arborist can discuss fertilization options, including our comprehensive, year-round Plant Health Care programs. Contact us to make sure you are taking the best care of your damaged trees.

Extensive defoliation, or loss of leaves, is common after severe storms with heavy rain, wind, and hail. While the leaves should grow back, the tree’s ability to take up nutrients and water from the soil is greatly impaired

While fertilization goes a long way toward helping damaged trees recover, they are also more susceptible to disease and pest infestations. With the recent wet weather, fungal issues are increasingly common, but insect activity and environmental stress are also a danger. Over the coming months and years, we expect to see:

Tree Failure and Death in Some Cases

While trees have the ability to store energy to last them for years, as these stores are depleted due to damage and infestation, the trees will slowly die.

Oak Wilt

Already a major concern in North Texas, the oak wilt-carrying beetles are drawn to open wounds and damaged areas. Until we have temperatures consistently above 90 degrees, the beetles and the fungus they carry will remain active.

Sunburn and Sun Scald

With reduced leafy canopy, the branches and trunks of trees will be exposed to more direct sunlight, which can cause further damage. Red oaks are especially prone to sun-related damage.

More Broken Limbs and Tree Damage

Trees grow in response to their surrounding, especially other trees. When one tree in a group is damaged or removed, other trees are exposed to the environment in ways they have not been before. As future storms and wind move through the area, the newly-exposed trees may not be adapted to their exposed conditions, and may not be able to withstand the elements. Ask your arborist to see if tree cabling and bracing might be recommended to reinforce your trees.

As you are considering fertilization, also talk to your arborist about treatment for fungi, bacteria, and pests. While treatments have varying effectiveness, depending on the specific situation, your arborist can discuss options for your trees. Contact us to have an arborist come out for a post-storm assessment.

After such a loss, the best remedial measure is to plant new trees. The best time to plant trees is the winter, so use the intervening months to consider where and what kind of trees to plant. It may not be the best idea to replace a removed tree with the same species. Talk to your arborist about types of trees that would thrive in your particular conditions, and to discuss the best place in your yard to plant a tree. (Even if you have had a tree removed, we don’t recommend replanting in the same place, as underground root systems may hinder the new tree’s growth.) Choose native species that can better cope with our North Texas weather. If you don’t have room for more trees, consider supporting a community organization that is replanting for those who need them.

The storm on Sunday, June 9th, 2019, damaged thousands of trees in Dallas, Richardson, Carrollton, Irving, and the surrounding areas. For many, this was the quickest, most devastating storm in recent memory. According to WFAA-TV meteorologist Pete Delkus, the winds increased to 63 MPH in only 5 minutes, with peak gusts at 71 MPH a few minutes later.

When the storm hit, one of our arborists was trapped in her home due to fallen branches, two staff members had flooded cars, two arborists were out of town, and our operations manager was stuck at a gas station, out of gas, waiting for the power to come back on. Our office was without power for three days, and those of us with power worked from home, the rest on the road, despite spotty cell service. Still, we tried to respond as quickly as we could, and have been able to assess over 700 properties for damage and deal with storm damage at nearly 200 homes. Visit our Facebook page for some photos of the damage we have seen!

At Texas Tree Surgeons, we love trees, and we hate to see such widespread damage. We are proud to call North Texas home, and we are grateful for the opportunity to care for your trees, and the continued support of our community. If you ever have any questions or concerns about your trees, please let us know!

What is Oak Wilt?

by Texas Tree Surgeons Resources, Tree Health Care

What is Oak Wilt?

At Texas Tree Surgeons, we love trees and we love our customers, and we have created a series of articles covering tree basics. If you have a specific tree question, let us know!

Oak wilt, and the precautions that need to be taken to help prevent the spread of this fungal disease, may be the most often talked-about aspect of tree health care in Texas. Throughout the state, tree owners and communities are challenged by the potential devastation to all species of oak tree. In some areas, there are ordinances in place that restrict oak trimming in order to prevent the spread of the disease. Other areas have no formal regulation, and this can lead to a lack of awareness and a potential for widespread infection.

While oak wilt is a serious threat to our North Texas urban forest, there are simple steps that everyone can take to lessen its impact.

What kind of Disease is oak wilt?

Oak wilt is an infectious disease caused by a fungus (Bretziella fagacearum*). All oaks (genus Quercus) are susceptible to oak wilt, but different species may react differently to the fungus. Oak wilt is a vascular disease, and infects the whole tree, even if only one part is symptomatic. As the fungus spread through the tree, it blocks the transmission of nutrients to the canopy, causing the characteristic “wilt,” or dieback.

In live oaks, infected leaves often show yellow-brown veins, even while still on the tree. In red oaks, leaves may simply wilt and brown. This process can lead to an autumn-like coloration during the summer. Additionally, fungal mats may form underneath the bark of red oaks, leading to cracking, peeling bark and a rotting smell.

While visual inspection is a strong indicator of the presence of the oak wilt fungus, laboratory confirmation may be required. The Texas Plant Disease Diagnostic Laboratory offers testing for oak wilt and many other diseases. For more information on how to submit a sample, see this post or contact your arborist.

Live oak leaves showing the venal necrosis characteristic of oak wilt

How do trees get oak wilt?

The most common ways for the oak wilt fungus to be transmitted are by insect activity and root grafting. Insects can infect a tree through any exposed wood (not covered by bark) or open wound (such as a pruning cut, broken limb, or where branches rub against each other). In situations with oaks planted in close proximity, the fungus can be transmitted from one tree to another via underground root grafting. As roots make contact with other roots, they grow together and share pathogens.

Different species of oak can contract and spread oak wilt by different methods.

RED OAKS

Red oaks (Texas, Shumard, blackjack, water) are extremely susceptible to infection through insect activity. Red oaks are often the primary mode by which oak wilt gains a foothold in a new area. The oak wilt fungus thrives in red oaks and creates visible fungal mats underneath the bark. These spore mats attract insects; sap beetles of the Nitidulidae family are the most common type. Beetles feed in the infected area and become covered with particles from the spore mats. Drawn to exposed wood on healthy trees, the beetles transfer the fungal spores, spreading the infection.

LIVE OAKS

In contrast to red oaks, live oaks are susceptible to oak wilt primarily through their root systems. In nature, live oaks often grow in groups, sometimes called motts. Underneath the mott, the root systems of the individual trees become interconnected. This grafting allows not only nutrients to be shared, but pathogens as well. Once a member of the mott has contracted the oak wilt fungus, the infection quickly spreads.

WHITE OAKS

White oaks (post, bur, chinkapin) are more resistant to oak wilt than other species, but are still at risk. Transmission generally occurs through spore transfer by insects, or by human activity.

Can you prevent Oak Wilt?

Oak wilt is an epidemic. Because of the concentration and susceptibility of oaks in Texas, especially red oaks, it can be difficult to isolate centers of infection and prevent further spread. The Texas A&M Forest Service and the Forest Health Protection branch of the U.S. Department of Agriculture have issued some guidelines to help prevent further tree death.

  • Remove and properly dispose of diseased red oaks immediately
    • Chip or bury all tree material
  • Do not transport unseasoned firewood
    • Firewood should be dry, splitting, and the bark should be peeling off
  • Do not store unseasoned oak firewood uncovered
    • Cover tightly with heavy, clear plastic and bury the edges to restrict insect access
  • Do not prune or otherwise wound oak trees from February 1 to July 1
    • The best time to trim is in the fall and winter
  • When infection is a risk, take proper precautions
    • Sterilize tools and paint cuts

If you have healthy oak trees in an area with infected trees, preventative treatment may be effective in slowing transmission. As oak wilt is a systemic, vascular disease, the most effective treatments consist of injecting the infected trees with a fungicidal chemical. The only currently recommended fungicide is Alamo®, a formulation of the fungicide propiconazole. The fungicide is administered through holes drilled in the root flare of the infected tree and should only be applied by Texas Department of Agriculture Licensed Applicators.

For large stands of oak trees, especially live oaks, trenching around the area and severing root connections can limit disease spread, as well.

A typical system for fungicidal injection; each green port is inserted into the living tissue of the tree.

Can you cure Oak Wilt?

There is no known cure for oak wilt. Reported home remedies or substances applied to the exterior of the tree have not be proven to have any remedial effect. If you have a tree that is infected with oak wilt, be sure to consult a Texas Oak Wilt Qualified arborist or your local Texas A&M Agrilife Extension agent to discuss treatment options.

Red oaks usually defoliate and die one to six months after becoming symptomatic. Live oaks may last up to a few years before total necrosis. White oaks show the most resistance to oak wilt and may survive several years after infection.

Fungicidal treatment may prolong the life of infected trees, but cannot eradicate the disease. However, systemic fungicides are most effective if a tree has not lost more than 30% of the crown. Contact a certified arborist to see if your tree may be a good candidate for treatment.

What areas have Oak Wilt?

In North Texas, there are many centers of infection. At Texas Tree Surgeons, we take oak wilt precautions throughout our service area. Still, there are a few neighborhoods in which we have seen particularly bad oak wilt activity:

  • Preston Hollow, Dallas
  • Lakewood, Dallas
  • Walnut Hill and Abrams, Dallas
  • Coit and Campbell, Richardson
  • President George Bush Turnpike and the Tollway, North Dallas
  • Park and US 75 in Plano
  • Highland Park
  • University Park

If you live in one of these areas, or suspect oak wilt activity in your neighborhood, contact your arborist to see what specific preventative steps are recommended for your trees.

Oak wilt is one of the greatest threats to trees in Texas. Education, awareness, and prevention are the best tools we have to protect our urban forest from devastation. If you want to learn more about oak wilt, visit TexasOakWilt.org.

At Texas Tree Surgeons, we love trees and we love our customers, and we believe that the more people learn about their trees, the better we can serve our community. We have several Oak Wilt Qualified arborists on staff; please let us know if you have any questions about oak wilt or any other tree question. We are always happy to help!

* – Until 2017, the oak wilt fungus was identified as Ceratocystis fagacearum.