All posts by Texas Tree Surgeons

Is Mulch Really That Important?

by Texas Tree Surgeons Resources, Tree Health Care

Is Mulch Really That Important?

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!

Mulch is an important part of tree care that is often overlooked. Many trees are surrounded by turf grass or other plants, which can stifle their growth. Proper mulching can be the key to trees that not just survive, but thrive.

In nature, trees live in a complex organic environment. A forest can be made up of hundreds of different plant and animal species, each contributing something to its surroundings. The forest floor is composed of layers of organic material, from fallen and rotting trees to tiny plants that serve as ground cover. This complexity provides a habitat for animals, plants, and microorganisms. In this environment, a tree is able to send out its roots into rich, fertile soil and get the exact nutrients it needs to thrive.

In our urban environment, trees are often in competition for resources with turf grass.  or may even be surrounded by non-organic materials, such as concrete. The soil around a tree can easily become compacted due to above-ground traffic. While we cannot completely re-create the forest environment in a city, we can help reduce soil compaction and competition by correctly mulching around trees. When mulch is properly applied and maintained, trees are able to grow sturdier root structures, tree health is improved, and we benefit from hardier trees that can live for decades.

Does the Type of Mulch Matter?

Despite the various ways that mulch is marketed, packaged, and sold, there are only two basic types: organic and inorganic. Organic mulch is made up of plant material, and can come from a variety of sources. Wood chips, bark, nut shells, and pine needles are common components. Inorganic mulch includes anything that is not plant or animal material and does not break down naturally. Crushed stone, recycled tires, and landscape fabric are common types. While inorganic materials can be useful in certain landscaping applications, they are not beneficial to trees, and may actually be harmful if used as tree mulch.

Choosing the best mulch requires understanding the needs of your tree and the underlying soil conditions. Soil density, pH, drainage, and composition all have an effect on the ability of a tree to send out roots and get the nutrients it requires. While mulch is not primarily a fertilizer, it is composed of organic matter. Insects, earthworms, and microorganisms break down the organic material become food for the tree. Mulch selection and maintenance can influence which types of organisms are able to survive in the mulched area and benefit (or harm) the tree.

Most commercially-available mulch is made from tree material that is shredded to a consistent size, partially composted, and often dyed brown, black, or red. Commercial mulch is generally long-lasting and a good basic mulch. We recommend sourcing mulch from a reliable local producer that does not use chemical treatments or dyes, but composts mulch naturally.

In addition to general-purpose mulch, many producers offer mulch produced from a particular material, which can be used to alter or amend the chemical composition of the soil. Pine bark, for example, is acidic, and cedar mulch contains cedar oil, which can be a natural insect repellent. Other materials, such as nut shells or pine needles, may be available and can be helpful when mulching a particular species. Contact your arborist to see about mulch producers in your area/

Can I Use Wood Chips or Grass Clippings as Mulch?

Tree care businesses or municipalities may sell wood chips produced as a waste product of tree trimming or removal. If you have tree work performed, the tree trimmers may leave wood chips behind. These chips can be a cost-effective way to get organic material, but are not identical to commercially-produced mulch. Best practice is to compost any fresh wood chips before using.

Grass clippings, leaves, and other landscape waste material should be thoroughly composted before use to help prevent weed growth and neutralize any chemical imbalances. Sawdust should likewise be composted first, but sawdust from treated lumber should never be used as mulch. If modifications to soil pH are recommended, certain materials can be added uncomposted to mulch to achieve the desired effect. Ask your arborist for any special needs your trees may have.

How Should Mulch Be Applied?

Whatever type of organic mulch is used, it must be properly applied to provide its full benefits. Mulch that is improperly applied may even do more harm to the tree than good. While the planting of a new tree is the ideal time to begin proper mulching, any tree can benefit from mulch. For some trees that are in compacted soil or with root girdling issues, it may be best to perform a root excavation (such as by airspading) before mulching. If you have any questions or concerns about your trees’ roots or wonder if they could benefit from root zone excavation, contact your arborist.

Whether your trees are young or old, new or well-established, follow these guidelines for effective mulching: 

  • Lay mulch to cover a radius of approximately three to ten feet from the trunk, depending on the tree size.
    • The dripline, or outer edge of the canopy, can be used as an estimate for the circumference of the critical root zone of the tree.
    • For smaller trees, measure the diameter of the trunk (in inches) and multiply by 1.5. This is the radius (in feet) of the critical area.
  • For greatest effectiveness, it is recommended to remove turf grass in the mulched area.
    • A tree that is newly planted or that has had root excavation performed will likely already have a good buffer between it and the turf. Established trees may have turf grass covering all or part of the natural root flare, which should be carefully removed.
  • Use organic mulch only.
    • Any brick, stone, or metal tree rings should be outside the critical root zone.
  • Install mulch to a depth of two to four inches within the dripline circle.
    • Too thin a layer will be less effective at retaining moisture and regulating soil temperature.
    • A layer that is too thick may keep the soil too moist and harbor harmful bacteria or fungi..
  • The mulch should not touch the trunk of the tree. Leave a margin of about four inches.
    • Organic matter piled up against the trunk (a “mulch volcano”) can cause the bark to retain too much moisture, leading to trunk and root rot.
  • If a tree needs more water, you can form an additional ring of mulch about halfway between the trunk and the edge of the mulch zone.
    • This “donut” will help to funnel water to the central roots of the tree.
    • Make sure that water does not pool against the trunk.
  • Refresh the mulch in late spring and in fall, or as needed.
    • Inspect regularly, especially after heavy rain or storms, and even out thin/thick patches.
    • When the whole area is reduced through decomposition, re-apply to original depth.
  • Expand the mulched area as the tree grows.
    • Keep covering all the way out to the dripline, if possible.

Mulch should be expanded as the tree grows, and refreshed regularly.

Mulch that is piled too thick can lead to excess soil moisture.

Mulch should not touch the trunk of tree, as this can lead to rot.

The Right Mulch for You

In North Texas, it is common to have fairly dense, clay-like soil that tends to be more alkaline than acidic. Ensuring good drainage during wet weather can be difficult. In dryer periods, the soil can harden and crack. Mulch can help create a stable, permeable layer that can regulate moisture better than the underlying soil. Mulch also insulates the shallow roots from swings in temperature that we can have during the spring and fall. Most native trees and shrubs are adapted to the natural soil pH and composition, and only need basic mulching. Other species, however, may benefit from slightly acidic mulch.

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 mulch. 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: Should I Worry About Mushrooms on My Tree?

by Texas Tree Surgeons Ask Texas Tree Surgeons, Tree Health Care
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,
There are some mushrooms growing up my tree’s trunk. Is that bad?

-K.N.

As we’ve mentioned before, all this rain has really been a mixed blessing. While we are happy to be safely out of drought conditions, many issues that we don’t see in drier weather have started presenting themselves. Fungi, which thrive in moist environments, have been growing rapidly, sometimes seeming to appear overnight. While a few toadstools in your yard may not indicate a serious problem, visible fungal growth on trees is something to be on the lookout for and may need to be addressed.

There are a wide variety of different fungal species that can live in the soil around trees. Some are beneficial, and are part of a healthy soil ecosystem. Others, however, can spread through a tree’s living tissue and cause health problems for the tree. We have seen problems with Chinese pistaches recently that are caused by a proliferation of fungi due to the wet weather. In the past few years, Italian cypresses have also been afflicted with health issues due to the spreading of a particular fungus. In both these cases, there were little or no warning signs or visible “mushroom” growth before the trees started browning and dying back. However, there are some fungal infections that exhibit visible growths and can be diagnosed before the tree is too far gone.

Kretzschmaria

The fungus Kretzschmaria deusta is a common cause of root rot. Hackberries are a North Texas tree species that is often susceptible to infection by Kretzschmaria. When fruiting in the spring, Kretzschmaria fungi appear gray or white, and may be confused with lichen. As they mature through the year, however, the fungal growths darken and can be harder to see. At any time of the year, black or gray growth near the base of a hackberry is a typical sign of a Kretzchmaria infection.

With Kretzschmaria, as with many fungi, looks can be deceiving, as even a small area of visible growth can indicate an extensive underground presence. If you see evidence of fungal activity at the base of a tree, the root system may already be infected to the point of structural failure, and the tree can be at risk of falling. A certified arborist can properly diagnose a Kretzschmaria infection and discuss options for dealing with the infected tree. Unfortunately, there is no treatment for Kretzschmaria, and an infected tree usually must be removed. It is possible to perform a root zone excavation and examine the extent of damage, but the tree will have come down eventually. It is better to remove a tree safely before it falls on its own.

Kretzschmaria is always present in the soil, and can infect a tree when there is root or trunk damage. Even a small cut in the bark can be an entry point for the microscopic fungal spores, so it is important to take care when displacing soil or doing landscaping work around a tree. Proper mulching in the critical root zone is a good way to protect the tree from bark damage.

The tell-tale gray and white of Kretzschmaria deusta.

The black on the tree trunk was a Kretzschmaria infection that weakened the root system and caused this tree to fall in a storm.

Ganoderma

Ganoderma is the name of a genus of fungi, and there are several different species that are present in the environment. While the different species vary in appearance, the ones commonly seen in North Texas generally mature into ear-shaped growths called “conks.” The conks may appear on a tree trunk, near the base, or even grow right out of the ground. The conks begin as white- or light-colored, but darken into dark orange or brown with a shiny appearance on top. Oaks and elms are particularly susceptible to Ganoderma, but other species can become infected, as well.

Ganoderma, like Kretzschmaria, is present in the soil, and infects a tree when its roots become damaged and lose their protective bark. While Ganoderma is similarly untreatable, it can be easier to detect in its early stages and may be able to be managed, avoiding immediate removal. Root zone excavation can also be helpful in determining the extent of damage.

Mature Ganoderma conks
Ganoderma conks can sprout from the ground where the infected root material is close to the surface.

ARE ALL MUSHROOMS BAD?

While Kretzschmaria and Ganoderma can cause serious tree stability and health problems, not all visible fungi are a hazard. Fungi in the genus Laetiporus (such as sulfur shelf or chicken of the woods mushrooms) can live on a tree trunk for years without harming the tree. Common white toadstools, such as those in the genus Lepiota, may appear in lawns as a result of beneficial fungal growth in the soil. In periods of heavy rain, species that are usually hidden underground may show visible growths. If you see mushrooms or other fungal growth in your yard or on your tree, send us a photo, and we are happy to let you know if it’s something to be worried about. We love trees and we love our customers, and we always want to help you understand the complex ecology of our urban forest.

Have a specific tree question? Let us know, and you may see it answered in a future Ask Texas Tree Surgeons installment!

Want a Free Tree? [UPDATED]

by Texas Tree Surgeons Events, Resources

There are two programs in North Texas this fall to help beautify our neighborhoods by providing free trees!

For Dallas residents, the City of Dallas is introducing a new program called “Branch Out Dallas” on Saturday, October 27th. City officials and representatives of Texas A&M AgriLife Extension Service will discuss the benefits of trees for urban environments and providing an overview of tree care. The first 100 free trees of the new program will be handed out, with expanding availability between November 1, 2018 and January 11, 2019.

The kick-off event will take place at 10 am, Saturday, October 27th at

Kiestwood Assembly of God
2716 Kiest Blvd
Dallas TX 75233

For more information, visit this link.

The city has posted information to register for the free tree giveaway. check out the post at Green Dallas to sign up!

If you are not a Dallas resident, you can request a free tree through a partnership of Oncor and the Arbor Day Foundation. Trees can be mailed or can be delivered, as available. Plantings will begin this fall.

Visit the Energy-Saving Trees site to see what trees are available in your area!

At Texas Tree Surgeons, we love trees and we love our customers, and we are excited about these local programs to encourage tree planting! If you have any questions about the best way to plant a tree, or any other tree questions, let us know!

What is Stump Grinding?

by Texas Tree Surgeons Resources, Tree Removal

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]

by Texas Tree Surgeons Ask Texas Tree Surgeons
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.

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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!

Ask Texas Tree Surgeons: What’s All the Stuff Dripping on My Car and Patio?

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

Texas Tree Surgeons answers another question about trees in North Texas. Do you have a question, or would you like to have a visit from an arborist? Let us know!

I park under a tree a few times a week, and have been noticing little drops all over my windshield. Are the trees dripping sap on my car? Are the trees sick?

-S.J.

View from car window with residue on it

Is this what your car windows are starting to look like? You’re not alone…

If you park under trees this time of year, you may be noticing a slightly sticky residue on your windows. A similar substance may also be on your outdoor furniture. Since it seems to be coming from trees, sap is the first thing people think of. While trees can leak sap as a sign of infection, the sap is usually contained to a particular section on a tree limb or trunk, and doesn’t drip over a large area under the canopy. Tree sap is also much thicker and stickier than what we are seeing on cars lately. If you’re able to wipe the residue away with water or a little washer fluid, it’s probably not sap.

Ok, if it’s not sap, what is it?

Like our previous question about little twigs and leaves dropping out of season, the dripping is not a sign of a health issue with the tree, but is evidence of insect activity. While we can’t be certain of the exact insect without examining the tree, the most likely culprit is aphids.

Aphids are a problem for gardens and trees everywhere. Aphids eat sap from leaves and stems, and reproduce faster than any other insect. As they feed, they process the sap and turn it into a substance called “honeydew.” Honeydew is essentially sugar water, and is actually harvested by certain species of ants. Accumulations of honeydew on plants, especially crape myrtles, can lead to the growth of an unsightly black mold. A few species of aphids can also carry plant viruses.

If you haven’t guessed yet, what you’re seeing on your car is honeydew. As the aphids feed, the leaves and twigs can become covered in honeydew, which eventually starts to drip from the trees. Crape myrtles are a common victim of aphids, so they often drip more honeydew than other trees, but aphid activity in any tree can lead to honeydew and sooty mold.

So, how do you stop aphids from making a mess of everything?

The best control for aphids is actually the environment itself. Aphids have many natural predators, such as lady beetles (ladybugs), and they are very susceptible to changes in the weather. The lifespan of an aphid is about one month, so populations can die out quickly. In many cases, then, the best course of action may be to simply do nothing.

If further aphid control is needed, it is best to use biological and non-toxic measures. On smaller plants, a heavy water spray can dislodge aphids. Lady beetle larvae can be introduced to the environment and can quickly reduce aphid populations.

Insecticidal soaps and other surface insecticides (such as foliar sprays) can also be used to interrupt the aphid life cycle. However, these measures do not control adult aphids, and so they may be ineffective once the population has matured. Systemic insecticides are not effective against aphids.

Unfortunately, once the honeydew production has reached a high enough level that things are getting messy, the aphid population is probably past the point of effective insecticidal control. A heavy spray of water throughout the canopy may reduce the dripping, at least temporarily. Most likely, the honeydew will stop falling in the next couple of weeks.

Are you sure it’s aphids?

Of course, aphids are not the only source of residue falling from trees, but they are the one we see most often. We are always happy to come out and take a look at your trees and verify that there is nothing more serious to worry about. Unfortunately, we don’t provide any aphid controls that would be effective this season, but we can do some surface treatments on crape myrtles during the winter to help control the spring insect populations. Get in touch with us and we can have an arborist see which options might be best for you.

Keep those questions coming! At Texas Tree Surgeons, we love trees and we love our customers, and we want to do all we can to spread tree knowledge!