How Can I Help My Trees During a Drought?

Residents of North Texas are familiar with long, hot summers that take a toll on everyone and everything. From drinking extra water, keeping our pets cool, and making sure our air conditioners are working, summer in DFW can be a busy time. While watering our lawns is common practice, many homeowners do not think about the water needs of their trees. During a Texas summer, and especially when we are in drought conditions, providing adequate tree care is critical to helping your trees survive and thrive.

How Does Drought Affect Trees?

Trees are able to store water and nutrients and so may not show signs of drought stress immediately, at least not to a casual observer. When trees are greatly affected by lack of water, these symptoms are common:

  • Yellowing, wilting and browning leaves
    • Leaves turning colors other than green (except in species that exhibit other colors of foliage) is often the first sign that something is wrong with a tree
  • Leaf drop/defoliation
    • Keep in mind that some species (like live oaks and magnolias) exchange leaves throughout the year, rather than all in the fall, so some leaf drop is natural
  • Dieback at the end of branches and limbs
    • As a tree loses vitality, the smaller growth is often the first to die
  • Sunburn
    • As the canopy loses leaves, larger parts of the tree become exposed to sunlight
    • Constant exposure to light and heat causes damage to the outer layers of bark, which can start to die and fall off, exposing the nutrient-carrying parts of the tree to more heat and sun

Even when visible signs are not present, trees experience stress soon after their needs for water are not met. Some of the “invisible” signs of drought stress are:

  • Death of fine, nutrient-absorbing roots
    • In addition to the large stabilizing roots, trees have fine, hair-like root structures in the top layers of soil that absorb water and nutrients
    • These roots die quickly when the soil around them becomes dry and hot
    • As these roos die, the tree loses its ability to take up moisture and nutrients from the soil, leading to further stress and dieback
  • Reduced ability to fight off diseases and pests
    • If a tree is losing energy due to a lack of incoming moisture and nutrients, its defenses are less able to resist other attacks and stressors
    • If bark is being lost, pests that feed on the heartwood have easier access
  • Stressors that are normally insignificant can become big issues
    • The impacts of unnecessary removal of green wood, damage to the canopy or root system, and stress from nearby activity (such as construction) are amplified by drought stress

What Can I Do to Help My Trees in a Drought?

Water. Water. Water!

The most important thing to do to help your trees is water them.

  • A lawn sprinkler system is NOT enough to keep trees hydrated.
    • Trees need much more water than turf grass or smaller plants, and must be watered correctly, if there is to be any effect.
  • North Texas Tree Watering Guide

Use Mulch to Regulate Soil Temperature and Moisture

Proper use of mulch around trees reduces the amount of watering needed and provides vital nutrients to the soil and tree roots underneath.

What to Avoid in a Drought (and Always!)

DO NOT Use High-Nitrogen Fertilizer

  • Nitrogen stimulates rapid growth, which expends a tree’s depleted energy stores quickly

DO NOT Use “Weed and Feed” Products

  • The “weed” component is a tree-targeting herbicide, and the “feed” is often a nitrogen-based growth stimulant

DO NOT Over Trim Trees

  • Avoid unnecessary trimming and removing too much of the canopy, which reduces a tree’s ability to draw up moisture and exposes the branches to the sun

DO NOT Disturb the Area Under a Tree’s Canopy (Critical Root Zone)

  • Digging, trenching, planting, construction, and other activity can destroy the fine, nutrient-absorbing roots and even damage larger roots, leading to instability

How Arborists Help in a Drought

Whether your tree is showing signs of lack of water, or is withstanding drought stress, proper tree care from an ISA Certified Arborist® is crucial to giving your trees the best chance to survive a drought.

  • Proper trimming to remove dead or diseased wood, and provide airflow to keep the canopy cool
  • Applying organic soil amendments designed to help drought-stressed trees supplement any lack of nutrients in the environment
  • In cases of root damage, pest activity, or heat-related diseases, recommending plant health care programs designed to reduce stress and encourage healthy growth
  • Reminding you to water!

Proper summer tree care (especially watering!) is the key to keeping fine root structures alive so that trees are able to get the water and nutrients they need to survive a drought. The top two to four inches of soil around the base of a tree and under the canopy is where a tree gets most of what it needs to grow. Keeping that area stable, watered, and cool goes a long way toward having trees that thrive even in a North Texas summer.

At Texas Tree Surgeons, we love trees and we love our community! The Texas drought in 2011 killed an estimated 300 million trees, including 5.6 million urban shade trees. We are keeping an eye on Texas drought conditions and adjusting our recommendations and practices accordingly. If you are concerned about your trees or have questions about how best to care for them, one of our ISA Certified Arborists® would be glad to talk to you! Contact us today!

Will My Trees Survive Freezing Temps and Winter Weather?

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!

Ask Texas Tree Surgeons: Why Do My Red Tip Photinias Have Spots on the Leaves?

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!

What is Oak Wilt?

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!

What is Stump Grinding?

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!

When providing a proposal for a tree removal, our arborists also evaluate the site for stump grinding. While having the stump ground is not always necessary, many people prefer to deal with the stump at the same time as having the tree removed. Stump grinding allows the property owner to use the area where the tree once stood for laying sod or planting a flower bed. The stump grinder also produces mulch that has many uses around the yard. Here are answers to some common questions we get about stump grinding.

Non-natural material, such as this lighting cable, may reduce grinding depth.

How deep CAN THE stump grinder go?

We generally grind four to six inches below grade (ground level). If deeper grinding is needed, it can be requested, although the price of stump grinding may increase. The depth to which a stump can be ground is subject to some limitations, however.

  • The stump-grinding blade has a diameter of about 10 inches, and can only be maneuvered up and down within a specific range.
  • A tree that grew in shallow soil, such as over the limestone bedrock prevalent in the Dallas area, may not have six inches of grindable depth.
  • Other material near or around the tree may limit how deep the grinder can go. While the stump grinder is powerful, it is only designed to handle plant material, wood, and dirt. Take note of:
    • Fencing, concrete, brick, or rock around a stump (such as a tree ring)
    • Nearby trees that may have roots under the tree stump
    • Swimming pools, walkways, and patios that may prevent the grinder from reaching all of the root material
    • Lawn irrigation, sprinkler systems, tree lighting wiring, and buried hoses
  • We generally do not grind deep enough to risk interfering with properly-installed utility lines or buried cables, but unforeseen obstacles can be encountered that necessitate a shallower grind.

What exactly lies beneath the roots of a tree or the surrounding soil may be a mystery, even to the homeowner. While we are very careful when grinding a stump, we will not take responsible for damage to irrigation lines or other items located below ground that we are not aware of. It is important to inform your arborist of any sprinkler systems or other objects that might be in the area to be ground before the work begins.

Grinder blade in action; grind depth can be limited by blade size.

What is left after a stump is ground?

As the blade grinds the stump and surface roots, it produces a mulch made up of tree material and dirt. The mulch produced by stump grinding can take up a much greater volume than the original stump. (It can be helpful to think of the difference between a block of cheese and that same cheese after it is grated.)

Mulch from stump grinding is valuable organic material that decomposes more quickly than many other kinds of mulch, as there are generally smaller wood particles present, and more soil to help it break down. It is our standard practice to push the mulch back into the area that has been ground (“backfilling”). Even so, there is usually a large pile of mulch left above ground, often much more than the tree owner expected. Because of its composition, the mulch does settle fairly quickly, but many people prefer to use the mulch around their yards, rather than leaving it where the stump once was.

Stump grinder mulch can be used for composting or applied in flower beds. (Depending on exact composition of the mulch, it may not perform in the same way as typical hardwood mulch, and may need to be replaced sooner.) After some time, when the mulch has settled, it can be packed into the ground-out area, making the area ready to be prepped for laying sod or for planting a flower bed or other small plants. If requested, we can provide mulch bagging and/or bagged mulch haul-off as an additional service after stump grinding, but our standard practice is to leave all grinder mulch on-site.

A stump of about 50 inches before grinding…

…the mulch from the same stump after grinding. The mulch left after after a stump is ground makes a great addition to flower beds and compost piles.

Will the tree come back after A stump is ground?

Even with stump grinding, some species of tree can still send up shoots and new growth from the roots left below ground. Crape myrtles, chinaberry trees, hackberries, and Bradford pears are some common species in the area that can be very persistent in growing back. The sprouts that return after stump grinding can be trimmed or mown down and will eventually stop coming back, as the remaining roots use up their energy reserves. Commercially-available woody stem killer can be used to accelerate the dieback of the roots. White vinegar can also be used as an organic alternative to commercial root killer.

Can I replant after a stump is ground?

We are often contacted about removing a tree that the owner would like to replace. We do not recommend trying to re-plant trees in the same area where a tree was removed and the stump ground. Even with a deep grind, an extensive root system remains underground. The old root system can interfere with the new tree’s attempts to become established. Furthermore, if the old tree had a disease, that disease may still be present in the remaining root tissue, and can be transmitted to the new tree. When replanting is desired, we can discuss finding a location that is far enough from the removed tree to lessen the likelihood of interference from the old root system. If homeowners’ association or municipal restrictions require a tree to be replaced in a certain location, excavation or hand digging may be the only options.

When a tree falls, the root and stump area can be difficult to grind.

Can every stump be ground?

In the case of a tree becoming uprooted (because of storm damage or root rot, for example), the stump cannot be dealt with as easily. If there is a large amount of root material above ground, the stump grinder may be physically unable to reach it. Depending on the type of tree and how it grew, it may pull up a great deal of dirt, turf grass, and other underground material when it falls. What is left after grinding an uprooted stump may be more dirt than tree matter, and may not be suitable for use as mulch.

Weather is also a factor that can determine how and when stump grinding can be performed. A long period of rain can cause the soil to become waterlogged. Operating a stump grinder in heavy, wet soil can not only make a bigger mess than usual, but can damage the surrounding area due to the weight of the machine. It may be necessary to wait until the area dries out before attempting even a “standard” stump grind.

If a customer has a special circumstance, like an uprooted tree, or there are multiple stumps in one area to be ground, we always send an arborist to assess the situation before providing a quote or scheduling the stump grinder.

How much does stump grinding cost?

The cost of stump grinding is dependent upon three main factors: the size of the stump, the location of the stump, and how deep the grinder needs to go. While we generally provide a stump grinding price when we give a quote for tree removal, we are also happy to evaluate any other stumps you may want to have ground.

How DO I MEASURE A STUMP?

The base cost for stump grinding is determined by the diameter of the stump in inches, including any above-ground roots. This measurement can be taken before or after a tree is removed. To get the right measurement, it is important to go “from dirt to dirt.” This means measuring from the stump edge or root point (where it touches the dirt) farthest from the trunk to the opposite edge or root point. It is also important to measure from different directions and to take an average measurement, as this most accurately reflects the area to be ground. The “dirt-to-dirt” measurement can be quite a bit larger than the diameter of the tree trunk, and we do see situations where the stump grinding is more costly than removing the above-ground tree.

Surface roots need to be included in the stump measurement.

This is a 75-inch stump, measured “dirt to dirt” at the yellow line. Measuring on the trunk is inaccurate: if this tree were measured at the red line, the result would only be 37 inches, which is not the actual area to be ground.

Even after a tree is cut down, properly measuring a stump can be tricky when there is a root flare and surrounding vegetation.

Can the stump grinder reach my stump?

Our standard stump grinder is a machine that is seven feet long and three feet wide. At the front is a rounded blade (similar to the tip of a chainsaw) that chips away wood as it moves across the stump. The stump grinder is designed to fit through standard gates, but some older or narrow gates may not be able to accommodate it. The weight of the machine may also prevent it from reaching certain areas without damaging walkways or ground cover. While the grinding blade has some maneuverability, clearance of at least seven feet on one side of the stump is required to allow the grinder to access the area to be ground. In smaller areas with less clearance, it is possible to use our smaller stump grinder, but this can increase the time and cost of the procedure.

Stump grinder blade

Can i just leave the stump?

Iit is not necessary to grind or otherwise remove a stump after a tree is taken down. We have customers who request a tree not be cut all the way to ground level, and use the remaining stump as a plant stand, table base, or just a yard feature. Even if the stump is cut close to the ground, it can last several years. Preservative coatings can also be applied to prolong the life of a standing stump.

Some homeowners prefer to let a stump decompose naturally over time. Old stumps can become habitats for fungi, insects, and other creatures. As the stump breaks down, it can become rich organic material that can be added to compost or used in planting. If a stump is left unground, however, it can continue to send out new growth for years after the tree has been removed. Drilling holes in the stump and filling with Epsom salt or using commercial stump killer can accelerate stump dieback, but those chemicals can be toxic to surrounding plant life. Treating the stump with chemicals can also make the area hazardous to people and pets.

A stump left to decay naturally. The tree was removed approximately 5 years ago. (Photo courtesy Tom Davis)

More Questions about stumps? Let us know!

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 hope this article has helped answer your questions about stump grinding and what your options might be. If you have any specific questions, let us know, and we’ll be happy to send an arborist out to evaluate your needs and offer our suggestions and expertise.

Ask Texas Tree Surgeons: What’s Wrong with My Chinese Pistache? [UPDATED]

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,

My Chinese pistaches are looking terrible! The leaves are yellowing, the berries are black, and it looks like it’s dying. What’s going on?

Chinese pistache tree with dieback

Extensive dieback on a Chinese pistache

-A.B.

For many years, the Chinese pistache (Pistacia chinensis) has been well-regarded as a landscape shade tree for urban environments in Texas. Although native to China, this species of pistache (related to the nut-bearing pistachio tree) can thrive in a variety of conditions. The Chinese pistache is a fast grower and is resistant to heat, drought, and alkaline soil, all common in North Texas. Like the native red oak, the Chinese pistache is a reliable source of fall color. The dark red berries that female Chinese pistaches produce are not only striking, but can attract birds and other wildlife. For many builders and landscapers, the Chinese pistache is a go-to choice.

Chinese pistache leaves with spotting

If a tree’s leaves are showing spotting or uneven color change, it can be a sign of a problem.

This year, however, we have been seeing unprecedented dieback and wilting of leaves and berries in Chinese pistaches. Entire trees are exhibiting leaf spotting and extensive browning. Similar to the browning present in Italian cypresses the past two years, it seems that the Chinese pistache dieback is caused by a fungus. And much like the Italian cypress issues, there may not be much that can be done at this point.

Water, Water Everywhere

Recent wet weather, combined with poor drainage in clay soils, creates a “wet feet” situation in trees, where their roots are inundated with too much moisture. Trees that are not suited to wet soils are not able to regulate the high moisture level in their roots effectively. The roots then become susceptible to pests, especially fungi, which thrive in damp, poorly-drained soil. As the tree root tissue becomes waterlogged, the fungi are able to gain a foothold in the roots and begin infecting the tree internally. Eventually, the tree’s vascular system itself becomes the mechanism by which the fungal spores are spread throughout the branches, leaves, and fruit. The fungus disrupts cell function in the above-ground parts of the tree, just as it did in the roots.

Chinese pistache berries with infection

Infected berries will rapidly change from red to black

What Can We Do About It?

Unfortunately, there is often little that can be done to improve overall drainage in clay soil. Still, there are some things that tree owners can do to give their trees the best chance:

  • Select native species that are well-adjusted to the North Texas climate
  • When planting, do not plant too deep, and follow good mulching practices
  • For established trees, do not overplant the area near the root collar and inside the drip line with turf grass or other groundcover
  • Consider root collar excavation (Airspading) for trees that were planted too deep
  • Vertical mulching and soil aeration can help break up heavy clay and compacted ground
  • Stop watering and turn off sprinkler systems during periods of heavy rain

Sometimes, despite best practices, fungal infections cannot be avoided. At the first signs of leaf spotting, or unseasonal browning or wilting, contact a certified arborist to diagnose any issues with your trees. Your arborist can suggest a plant health care program. Fungicidal treatments can be helpful, but must be timed appropriately. Once a tree shows extensive browning or dieback, it is often too late for fungicides to be effective.

If It’s Too Late…

If your trees are covered in dead berries and have dropped a lot of leaves already, it is unlikely that a fungicide would have much effect. The best thing to do would be to remove any diseased material from the tree, do as much as you can to improve drainage, and begin a fertilization program. With a good winter freeze, the fungus should die off. In the spring, reevaluate the tree for early signs of new or lingering fungal activity, and treat as appropriate.

At Texas Tree Surgeons, we love trees, and we hate to see a new problem arise that affects a common and much-relied-upon tree like the Chinese pistache. We have submitted samples to the Texas Plant Disease Diagnostic Lab and are awaiting the results. With proper identification, we may be able to better control the particular fungus in the future. We will be sure to let you know what we find out. Keep an eye on our Facebook page for updates!


—-

We received our results from Texas A&M. The samples we submitted from one Chinese pistache specimen showed evidence of both Phytophthera root rot and Anthracnose stress.

Phytophthera is a pathogen that causes damage to root tissue which can lead to the death of a tree. Phytophthera’s activity is enhanced by wet soil conditions and poor drainage. While fungicidal treatments can be applied, they will be of little benefit unless the underlying moisture and drainage issues are corrected.

Anthracnose is cause by a fungal pathogen, and can take advantage of plants that are already weakened by other stressors. The best method of managing anthracnose is to clean up and dispose of any fallen infected leaves or berries. Fungal sprays may be applied, but are generally not recommended during late summer or autumn, as the trees are preparing to go dormant for the winter, and the fungus should decline naturally.

—-

As always, please let us know if you have any tree questions. We are always happy to have a certified arborist come out and take a look a small issue to hopefully stop it from becoming a big problem!