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.

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.

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!

Another installment in our series of posts where Texas Tree Surgeons answers your tree questions. Are you having problems with your trees and want to know what’s wrong? Let us know!

Dear Texas Tree Surgeons,

A lot of my bushes, especially the red tip photinias, are starting to wilt and have reddish-brown spots on their leaves. What can I do about that?

Red Tip Photinias have long been a staple of North Texas flowerbeds and hedgerows. Hardy and fast-growing, the evergreen shrub can be trimmed to various heights and forms a good privacy barrier with its broad leaves. New growth has red leaves, giving the red tip photinia its name. Unfortunately, red tip photinias are particularly susceptible to leaf spot diseases.

This fungus Entomosporium mespili causes leaf spot on all members of the rose family, including red tip photinias. Starting as a red, brown, or black dot on leaves, the leaf spot expands outward as the fungus grows. Eventually, the red spots turn into a gray area rimmed by red. As the fungus spreads, it disrupts vascular function in the leaves, which eventually fall. The fallen leaves collect moisture at the base of the shrub, increasing fungal growth. As wet conditions continue, the fungus can spread its spores within water droplets, such as splashing from rain or irrigation. Left unaddressed, the fungus will spread throughout the photinias, causing wilting and dieback.

Environmental control

The first line of defense against fungal leaf spot, as with many fungal diseases, is to monitor watering and drainage. Fungi thrive in wet conditions of a moderate temperature, so the spring and fall are when we see the most activity. In periods of wet weather, the clay soil common to much of North Texas can hamper proper drainage, causing the area around the red tip photinias to become waterlogged. This moisture, mixed with the fallen and decaying organic material creates the ideal conditions for fungal growth. Even if the soil drainage cannot be improved, it is important to curtail watering so as not to make the situation worse.

In addition to moisture, the fallen photinia leaves contribute to the growth of the Entomosporium fungus. Keeping the area around the plants clear of debris can help slow fungal progression. In a similar way, dense foliar growth on the interior of the red tip photinias can collect moisture. Where possible, thin out dense areas to allow light and air to circulate. When trimming, make sure to remove any areas already showing leaf spot. Removed material, especially infected leaves, should be buried or disposed of in a plastic bag.

Chemical Control

Fungicides can be used to control Entomosporium leaf spot, but the process can be costly. Furthermore, treatment will be ultimately ineffective if the environmental factors are not eliminated. For valuable hedges, a continuous process of multiple-week treatments in the spring and fall may be recommended. In other situations, it can often be more cost-effective and better in the long-term to remove the affected plants and replace with a less-susceptible species. 

While there is no quick solution for red tip photinia leaf spot, we hope this information can help homeowners mitigate the damage to their shrubs, and decide if treatment or removal might be warranted. At Texas Tree Surgeons, we love trees (and shrubs! and hedges!) and we love our customers, and we always want to give our community the best, most accurate information regarding their plants. If you would like one of our arborists to come out and see how your photinias, or anything else, are doing, let us know!

As we prepare for storm season, Texas Tree Surgeons has a few tips for taking the best care of your trees. Let us know if you have questions or need us to come out to assess your trees!

Consult a Certified Arborist to Assess Any Storm Damage

Storms, especially ones with high winds and hail, can cause extensive damage to trees. After the storm, it is important to remove any damaged or fallen limbs, and to clean up the wounds from damage. If the tree is at risk for oak wilt or other diseases, it is critical to clean up wounds and seal cuts. See our post on storm damage.

Water and Fertilize After the Storms Have Passed

After any flooding has receeded, and the ground returns to its usual moisture levels, it is important to begin a water regimen for damaged trees. Damage to tree tissue can reduce the tree’s ability to pull water and nutrients from the soil. Additionally, consider fertilizer to increase availability of nutrients in the soil.

Special Note About Hail

Hail can defoliate trees and cause damage to the outer layers of tree bark. The loss of leaves and damage to vascular tissue can severely limit the tree’s ability to use nutrients. Healthy trees can recover, but trees with underlying issues or stressors may have a hard time bouncing back.

Watch for Signs of Stress

Just like after construction, it can take weeks or months for trees to show signs of stress from storm damage. Yellowing leaves, dieback, and limb discoloration are some signs of stress. If you see any of these signs, or have any other questions about your tree’s health, consult a certified arborist.

At Texas Tree Surgeons, we love trees and we love our customers, and we want to help our beautiful North Texas trees weather any storms that may come. As always, let us know if you have any questions or would like a visit from a certified arborist — storm damage or not.

Is mulch really that important? As discussed in our article on proper mulching, there is a big difference between urban soil and trees’ natural habitat. Mulching can greatly improve the quality of soil around a tree, but it is not always possible to properly mulch around every tree. In those cases, or when faster results are desired, fertilizers can be used to increase the nutrient content of soil to better enable a tree to thrive.

Why Do My Trees Need Fertilizer?

For most of North Texas, our urban soil is a dark-gray or black alkaline clay. This type of soil is prone to compaction, and often cracks during long dry spells. Furthermore, much of the area sits on relatively shallow limestone bedrock. These conditions create a high competition for nutrients in the top layer of soil, as roots may be unable to grow deeper due to compaction and rock.

A note about tree roots:

Generally, tree roots serve two main functions: absorbing nutrients and providing stability. The stabilizing roots are the ones people most often think of, as they are usually larger than the feeding roots and can grow deep into the ground. The feeding roots, on the other hand, are finer and are primarily located in the top several inches of soil, where the most nutrients are usually found. So, when providing nutrients to a tree, it is critical to fertilize the shallow feeding roots, and less so to reach the deeper stabilizing root system.

Proper mulching and using compost to improve the soil condition are key to providing trees with an environment in which they can thrive. Most trees and shrubs would also benefit from fertilization, especially when in competition with turf grass, or when there is inorganic material surrounding a tree that prevents nutrients from reaching the soil.

What is the Best Way to Fertilize Trees?

A note about synthetic turf:

The use of synthetic turf around a tree can prevent proper soil development and make fertilizer difficult to apply. Usually, the synthetic turf needs to be pulled back from the root zone of the tree to allow for a soil drench, or the deep-root feeder rod will have to puncture through the turf and any substrate to reach the real soil. Additionally, synthetic turf can have lasting negative effects on trees, as the material prevents nutrients from reaching the soil.

In certain cases, direct application of a liquid fertilizer to a tree might be used. Using a foliar spray can make nutrients immediately available to leaves to aid photosynthesis. Trunk injections can introduce nutrients directly into the tree’s vascular system, bypassing the roots. These two methods are not long-term solutions, however, as they do nothing to improve soil quality. Once the applied fertilizer has been utilized, the tree will return to its previous state if a consistent supply of nutrients is not provided.

What Kind of Fertilizer is Best for Trees?

While there are many commercially-available fertilizers, they are not all equally effective, and care should be taken before applying. Fertilizers engineered for turf grass development may not help trees, and may, in fact, harm them. So-called “weed and feed” fertilizers contain herbicides that can target woody-stem plants. If applied in the root zone of a tree or shrub, these herbicides can cause stress or even dieback.

Subsurface application of dry fertilizers, including the use of fertilizer spikes, is usually inadvisable. Even when properly watered, pockets of fertilizer material or spikes do not readily break down, and cannot effectively move through the soil. As a result, the soil develops areas of high chemical concentration surrounded by areas that lack nutrients. This chemical imbalance can lead to severe fertilizer burn and can cause more harm than good.

Organic vs. Inorganic Fertilizer

Inorganic fertilizer is a solid or liquid product that is chemically formulated to add specific concentrations of nutrients to the soil. Inorganic fertilizers are generally labeled with three numbers (called “NPK” numbers), which indicate the relative content of nitrogen, phosphorous, and potassium, in that order. Inorganic fertilizers are used for their consistency and because they generally contain higher concentrations of NPK macronutrients than organic materials. However, because of the high percentages of certain chemicals, inorganic fertilizers are more likely to cause “fertilizer burn” because of over-saturation of a particular element. Furthermore, runoff from chemical fertilizers can contaminate water and pose a hazard to wildlife. Before using an inorganic fertilizer, it is important to understand exactly what the soil needs, and apply the appropriate amount. Soil testing, such as provided by Texas A&M, can give a guideline for selecting an inorganic fertilizer that is suited to a particular situation.

Organic fertilizers are composed of natural organic matter. While mulch and compost can be considered organic fertilizers, the term usually refers to a solid or liquid that is produced to be a soil amendment. Compost tea, bone meal, manure, and biosolids are common examples of organic fertilizers. Organic fertilizers can contain both macronutrients (usually nitrogen, phosphorous, and potassium, or “NPK”) and micronutrients, but the concentrations of these nutrients are not always specified on the label. Additionally, some organic fertilizers may contain helpful microorganisms (such as bacteria and fungi) that can further enhance soil quality. Because organic fertilizers are produced through natural processes, they generally have lower NPK concentrations than inorganic. As a result, organic fertilizers are less likely to cause fertilizer burn and do not pose the same risk to the environment as inorganics.

A note about compost:

Compost is partially-decomposed organic material that is added to soil to increase nutrient concentration. Like mulch, compost can improve overall soil composition, unlike fertilizers, which generally help plants, but do not have long-term effects on soil quality. Compost and mulch can be combined with soil amendments like fertilizers to help plants in the short-term and improve the soil over time. If you live in an urban area and don’t have the time or space to compost yourself, consider using a compost co-op. If you are in the Dallas area, we recommend Turn Compost. Check out their website to see if they service your neighborhood!

At Texas Tree Surgeons, we have three distinct fertilizer and soil amendment formulations that are applied in the Spring, Summer, and Fall. Each seasonal treatment is designed to give trees the nutrients they need at each stage of the growing season. We can also add specific micronutrients (such as iron) for particular trees. Contact one of our certified arborists to get an estimate for a year-round fertilization program!

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.

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.

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.

Another installment in our series of posts where Texas Tree Surgeons answers your tree questions. Are you having problems with your trees and want to know what’s wrong? Let us know!

Dear Texas Tree Surgeons,

I’ve been hearing about the emerald ash borer, and it seems pretty serious; should I be worried?

-J.G.

You may have seen recent media coverage of the discovery of the emerald ash borer (“EAB”) in Texas. The emerald ash borer (Agrilus planipennis) is a small, green beetle that feeds on ash trees. Though native to Asia, EAB first appeared in North America in 2002. In 2016, EAB was found in northeast Texas. In July 2017, suspected EAB specimens were found in Tarrant County. In early December 2018, the Texas A&M Forest Service confirmed that several ash trees near Eagle Mountain Lake had been killed by EAB infestation. In May 2020, Texas A&M confirmed presence of EAB in the Denton area.

Should I be Concerned About Emerald Ash Borer?

The threat from EAB is a serious one, as ash trees make up between 5-13% of the DFW urban forest, and are important providers of shade and clean air. If you do have ash trees, however, EAB infestation can be prevented.

Emerald Ash Borer Prevention Tips

• If there are diseased or damaged ash trees, consider removal before they have a chance to be infested.
• If there is EAB activity within a few miles, consider preventative systemic insecticide treatment.
• Keep an eye out for signs of EAB activity:
  • Dead/dying branches in upper crown
  • Shoots/suckers along trunk
  • Splitting bark with insect trails underneath
  • Increased woodpecker activity
  • D-shaped exit holes

Can Emerald Ash Borer be Treated?

Unfortunately, once an ash tree has been infested by EAB, there is little that can be done. Insecticide treatments can help slow the decline of the tree, but once more than 50% of the canopy is gone, treatments are not effective. EAB generally kills infested trees in two to five years.

So, yes, the emerald ash borer is a serious threat to ash trees, but education and awareness now can help mitigate its effects. If you have ash trees, take note of their appearance, and contact your arborist if you see any signs of decline. If you don’t have any ash trees, you do not need to worry about EAB at all.

For more information on EAB, visit the Texas A&M Forest Service. For help identifying your trees, visit Trees of Texas.

At Texas Tree Surgeons, we love trees and we love our community! The spread of emerald ash borer, while a threat to a small percentage of North Texas trees, is a threat that we can all help to fight against. If you have ash trees or know someone who does, let us know, and one of our ISA Certified Arborists will be happy to evaluate the trees for EAB risk factors and provide options to keep them safe and healthy.