Spanish Oaks in decline?

Tell them what you’re going to tell them:  Spanish oaks are decreasing in numbers aroundAustin.  Why does this matter?

In and around greater Austin, Spanish oaks can be found growing, especially on rocky slopes and in greenbelt areas. These trees grow in their natural niche among the ash junipers (cedars), native Texas ash trees, occasional live oaks and cedar elms.

What’s especially interesting about these greenbelt areas is that they are, as is typical in all forested areas, extremely dense when unbothered.  This state is important to the very survival of the Spanish oak’s efforts to grow on poor, often steep, rocky limestone slopes. Due to erosion and high limestone content, the soils in these areas are extremely shallow causing Spanish oak roots to grow in next to no soil.

Central Texas summers are extremely harsh with us experiencing little to no rainfall and often months of temperatures over 100 degrees. As the Spanish oak is fairly drought resistant, the leaves are still quite thin with a fair amount of surface area. The waxy cuticle over the leaf that helps prevent sun scald (sunburn) and water loss is comparatively thin on the Spanish oak leaf compared to other species.   Severely drought stressed Spanish oaks get bacterial leaf scorch, the technical term for sunburn, on the leaves, leading to defoliation and death. As we consider heat and drought conditions, it is also important to note how porous the limestone is.

So why does this matter? Well, limestone, unless non-porous, which is fairly rare around here (see perched water tables), generally does not retain water.  Instead, water permeates through the stone when it rains and whatever does not flow down slopes and off ridges and spurs, where the Spanish oaks are growing, will permeate right through the soil, providing no water retention. During the hottest summer months, by the day after a rain, the soil will often be bone dry the day after a rain, especially in 100+ degree dry heat.  Mulch formed by leaf litter and shedding plant parts, which helps ensure healthy roots and soils formation, is often either partially or completely washed away through erosion, further eliminating the possibility of water retention.

So how do these trees survive?  The short answer is symbiosis. Symbiosis occurs when one plant or animal species benefits another. In the harsh rocky slopes of the Austin greenbelts, Spanish oaks are found in the summer on the ‘edge’ or around the outside of the forested areas, where the natural forested areas end due to neighborhoods, developments, and cleared areas that are dying and defoliating. Why? The answer is actually very simple.

In the greenbelts, the trees grow very close together. Although tree and plant roots cross over and compete with each other in very little soil, it is important to note how the densely packed canopies cool the root zones. Evapotranspiration is the technical term for water being pulled through the vascular system and out the holes in the undersides of the leaves (stomates). In simple terms, these stomates open to exchange gasses and to allow a certain amount of water loss to cool the leaves. In very hot conditions, they close to stop this water loss.

When tree/plant roots are no longer in these shady greenbelt areas, they are now exposed to the direct heat of the summer sun on the now exposed roots for months at a time.  Because they cannot retain any water, and the surface of the thin Spanish oak leaves are comparatively large, they have to put more water through the stomates to cool the leaves enough to prevent sun-scald (bacterial leaf scorch).  Subsequently, they defoliate and sections of the tree start to decline. Eventually, this leads to mortality.

Are your Sycamores declining?

Why does the Austin area lose sycamore trees almost every summer?

Sycamores, Platanus occidentalis, are on the list of local Austin trees that are much less drought tolerant.  They enjoy cooler, wetter weather, lower temperatures and more water during the summer months. Most healthy sycamores in the Austin area enjoy shaded, mulched root zones, as opposed to exposed roots in the full sun.   They also thrive where extra water is applied during the hotter, dryer summer months.

Because their leaves are very large, wide, and thin, they require more water through the leaves as a cooling effect to prevent drying out and sun scald.   Sycamores are typically found in riparian zones (areas along rivers and streams), along lakes and water bodies, and generally areas with poorer drainage and more long standing water.

When sycamores in the Austin area are found along right of ways where water is a limiting factor during summer months, or where the radiant heat from the street exacerbates water loss, stresses typically occur.  Heat stress here is exacerbated by lack of mulch to the root zone, and direct summer sun shining on the root zone.

Heat stress problems show up as upper defoliation, as the leaves at the top of the tree burn off due to excessive heat at the top of the tree, and then cause the upper limbs to die off as they then dry.  This is usually associated with an inability to get enough water to the top of the tree.  Then, with no leaves to pull water through the wood and up into the upper sections, the wood simply dries out up there and dies.

In extreme cases, the stems can experience cracking and death, and the cambium dies and turns black, which is exposed as the bark breaks off.   In these cases, the tree either dies or becomes hazardous and needs to be removed.  This is especially true of  larger trees.

The best thing to do is to plant the trees in areas where they are either on shady streets or back from the street altogether in the center of a shady front yard, preferably not North facing, and preferably in a mulched bed.  Extra summer water is also a good idea during the extensive dry summer heat.

If sycamores are already in decline due to drought conditions, we recommend watering them and adding a thick 2-3 inch thick mulch layer to the root zone.  Monitoring them and maintaining a frequent watering schedule (in keeping with Austin watering laws) is also recommended.

Sometimes, simply planting a different species altogether is recommended due to the overall harshness of the planting area.  Other factors are can also be a play with declining trees.  If you are unsure what is happening to our trees, it is always best to call me out and get a proper diagnosis.

Is ball moss killing my live oaks in Austin?

I get this question very often.  People see the ball moss in the live oaks on the dead limbs and automatically think it is killing the branches and that it will eventually kill the tree if it is not removed.   The truth is that ball moss is an epiphyte, or air feeder, and is not parasitic to the tree.   Because it is growing inside the canopy in shady areas around here, it looks as though it is killing tree limbs, when in fact the limbs are dying naturally over time due to lack of sunlight penetration.  Unfortunately, many less reputable and/or uneducated sales representatives for some local tree care companies often use the interior limb death as a fear factor and a sales tool to sell extensive ball moss removal for their companies.

However, the truth about ball moss with respect to tree health is not always completely cut and dry.  I attended a seminar on ball moss about five years ago at Texas A&M by Dr. Todd Watson who is Urban Forest researcher at Texas Agricultural Experiment Station and an expert on mistletoe and ball moss (as well as a great guy).  When the class full of professional, certified arborists were asked if ball moss is detrimental to plant health, half of the class raised their hands and the other half did not (I did not).  This was very interesting.  The reason for the split had to do with where specifically in Texas the arborists were practicing.

In humid areas of Texas, especially around lakes and bodies of water, ball moss infestations can be huge.  In the Austin area, however, the air is dryer and even by water, the infestations are generally not as bad.   In humid areas where ball moss is severe, it can actually grow over the ends of limbs in the full sun, causing the branches to actually be shaded out at the tips and killing sections of the outer canopy.  In these instances, it needs to be pruned off or sprayed.

Here in Central Texas, the way I handle ball moss on live oaks is to prune it out of the trees.  The air is generally quite dry here, and the infestations are rarely severe.   Trees with larger amounts of dead wood that have formed since the last pruning cycle are more apt to have ball moss.  As the canopies thicken back up since the last pruning cycle, the interior limbs die due to lower of sunlight penetration, and more ball moss forms on these limbs, and often on the interior living limbs as well, although generally not to the same extent.

It is important for long-term tree health to remove dead limbs from the interior of oak trees over time, especially large dead limbs.  This then allows the trees to heal over and compartmentalize rot, helping to keep the living limbs healthy.   As the dead wood is removed, so goes the ball moss.   Since the trees generally do not form that much ball moss between pruning cycles, it is not an issue in most cases.   Since spraying is costly, does not address the pruning needs of the tree, and is generally not necessary due to mild infestations, you will rarely see ball moss spraying as a preventive measure around here.

Is oak wilt treatable and how?

Once oak wilt is diagnosed, many people are at a loss as to what to do.  In the course of my career here in Central Texas, upon being called onto a property, many people have told me that once live oaks get oak wilt, that they are untreatable and that they should just let them die.  This is simply not true.

The most important factor to diagnosing oak wilt is diagnosing it early. If you in any way think that your oaks may be in decline, immediately call me out to inspect them. At this point, I will be able to either eliminate the possibility altogether or, immediately diagnose the disease and start treatment right away.

The longer you wait, the more damage the fungus will do to the tree, and then a successful treatment is less likely. In some cases, even a 20 percent defoliation can be evidence that the disease has progressed too far, and a treatment will be unsuccessful. Generally speaking, when an infected oak is treated, if it takes in enough material, it tends to stay at the canopy density it has when it is treated. This is why you often see live oaks that have been treated looking so thin and defoliated.

We use Alamo fungicide, generally at 20 milliliters per liter, and generally only treat trees once they have been diagnosed with oak wilt, or are in a stand of oaks that are symptomatic.   Trees put on new rings of growth every year, creating thicker trunks, roots and branches, and new roots and shoots.  Since this is new living tissue, once the Alamo has been injected into the tree the new years subsequent growth does not contain the chemical, and is not protected. We used to recommend treatment initially as a preventive for five-year intervals, with re-application every five years thereafter. Now, we are recommending treatment every two years; but only when the trees are either symptomatic or at high risk of contracting the disease within 12 months after treatment.  We use the recommended Texas A&M macro-injection method.

On larger properties such as parks and ranches, or in certain neighborhoods, sometimes trenching can be a good idea.  When hundreds or even thousands of oaks are at risk from oak wilt infected trees on property perimeters, often root severing through trenching two feet deep is the best and most cost-effective option for keeping out the disease. This is NOT a panacea, and it will NOT keep beetles from spreading the disease to healthy trees under ideal conditions, but it CAN keep the disease out in certain instances. It is better undertaken where large natural areas and large amounts of trees make Alamo treatment economically unfeasible. In neighborhoods, streets and sewer lines are essentially trenches, and the disease is often confined to city blocks once new beetle infections occur.

Cabling and bracing trees

Central Texas Tree Care has installed hundreds of cables in Austin area trees over the last 10 years and I am very proud of our record. My staff is highly trained and seasoned in this area and we now properly install more cables every year than just about any other local company. The purpose of this article is not to be overly technical, but rather to explain to the average person that we know exactly what we are doing, what standards to follow and what hardware to use.

Cabling and bracing trees are scientifically approved methods for supporting trees with split crotches, or for trees that have limbs or crotches that are predisposed to failure. The International Society of Arboriculture, ISA standards for tree cabling that we follow are called the ANSI (American National Standards Institute, Inc.) A300 standards for supplemental support systems. When done properly, cabling and bracing will often save limbs or entire trees. They are generally considered permanent solutions, although constant re-inspection and monitoring/pruning is always recommended.

Cabling trees is generally done to tie in either limbs that are overextended (too long and heavy), or to tie in large limbs in the upper canopy to support weak or split main crotches. Cables are almost always installed in conjunction with canopy thinning to reduce the end weight of large horizontal sections.  Sometimes, come-alongs are also used to help pull together split crotches so the cables can be properly tied  in. Often with split trees, (although not always necessary) threaded through-bolts are installed through the split crotch for added support.

Through-bolts are used as anchors. These are galvanized metal bolts, with a fully enclosed ‘welded’ eye and are installed right through the limb to be supported. A hole is drilled through the limbs at exactly the right angle and then the bolt is slid through the limb. After the bolt is in place, a washer and a nut is then put into place on the back side of the limb. This practice makes for a very solid and permanent anchor solution that will not pull out of the tree or rust. Nor will it interfere with the natural expansion of the limb. Additionally, the ring on the inside will not break. With cheaper hardware, often the ring is not a welded eye and the cable pulls out during the first storm.

Once the anchor bolts have been installed, then the cables are tied to the anchor bolts using thimbles.  The two strongest ways to do this are either with ‘dead-end grips’ or twisty ties as we call them, or by bending and splicing the cable itself through and around the eye ring, then splicing it. Both of these methods are extremely strong and effective.

Most (not all) cables I see installed by other companies in the Austin area are installed incorrectly.  Almost every time, besides using inferior hardware, the cables are installed either too low in the tree or too far down the limb they are supposed to support. ANSI A300 standards specifically state that cables should be installed a minimum of two-thirds of the way from the crotch to the end of the limb being anchored.

The cables and bolts need to be the right size for the job. Large trees and limbs require larger bolts and larger diameter cables. Smaller trees require smaller diameter bolts and cables. Limbs that are being used to anchor the tree require large enough diameters to support the bolts, but conversely putting bolts that are too long into large diameter wood is often not correct either (too far down the limb).

Safety factors such as proximity to power lines or other utility lines are paramount. Metal cables conduct electricity and must never be installed in trees where power lines contact the tree. Also, metal cables can rub against themselves or tree limbs, so they must always be installed free from obstructions.

Trees with multiple large limbs and weak crotches often require multiple cables. Often triangle, box or ‘wheel and spoke’ systems have to be installed.  When more than one cable has to be anchored to the same limb, more than one anchor bolt must be installed (one for each cable). The anchor bolts must NOTbe closer together than the diameter of the limb being drilled. Note: For safety and power, we use gas powered drills with forward and reverse settings, instead of electric drills that require a dangerous power cord.

Although lag bolts are on the approved list of hardware for ANSI A300 cable systems, we prefer to stick to through-bolts. As an arborist with more than 15 years experience installing support systems, I find lag bolts to be unpredictable and weak anchors, especially in large trees. They often pop out in storms.  Although they work better, for example, in oak limbs that have stronger wood, and are significantly easier to install, I have seen them come out or generally fail too many times in stormy weather. I would NEVER recommend lag bolts in softer wooded trees other than oaks, mesquite or black walnut trees in this area and prefer not to use them at all.

Often cables are not necessary at all, and I have seen cables installed when they are not needed with startling regularity. Always get your trees evaluated first to see if they even need cabling or bracing. I often see other tree companies promoting them because the crews need the work and not because the tree in question actually needs a cable. Beware of unnecessary tree work! Contact us if you want an honest professional evaluation.

Fake grass under your trees?

Fake grass. When we think about fake grass, many of us think back to the astroturf in football stadiums, or the cheap fake grass they used to use in the grocery store produce sections or various department stores. The fact is that ‘fake’ or man-made grass has come a long way since then. Stick with me here.

Now, you can actually buy artificial grasses that look like fescues, buffalo grass, St. Augustine or Bermuda as well as many other species. Not only that, but there are actually companies out there that help you pick out what you like and actually install it for you! Install it, you ask?

A football field for a yard?

The first time I saw an artificial lawn in the Austin area I couldn’t believe it. I could not understand the appeal at the time, but had not really even thought about it before. Upon further reflection and after living through this record-setting drought, it’s all started making sense. The watering, the weeding, the chinch bug applications, the fungicide applications, the mowing, the edging, the fertilization, the yearly dillo dirt application, the watering, the watering, the watering…

It’s no wonder people are looking for other options. Standard xeriscaping is not for everyone. The goal here is water conservation and the reduction in fertilizer and chemical applications.  But, how can it be good for trees?  I thought it would be awful for trees, suffocating and sterilizing the tree roots. Boy, was I wrong!

Better than the real thing?

Artificial lawns are porous, allowing water and oxygen to get to the tree’s absorbing roots. Artificial grass has no roots to compete with tree roots. Weed killers, which are always used on lawns and which often kill trees outright via Roundup, weed and feed or other herbicides, are no longer needed. Pollution due to lawn mowers is eliminated.  Thousands or dollars per year are saved by the homeowner. So let me get this straight, the trees are actually happier and the homeowner saves money?  Exactly!

I never thought I would be touting artificial anything. I hate artificial Christmas trees, wreaths, etc.  In this case though, there are more than a few things to think about.  First, we live in a desert environment here in the Austin area, where everything has to be artificially watered in order to survive in the blistering dry summer heat. Droughts are constant. Water is expensive, and as you water the grass it grows and then has to be mowed and maintained.  Water is a limited resource and we all waste more of it than we should.   If not for irrigation, it would all be live oaks, cedars and cactus in the yard.

Think about this.  We treat water so that it is potable (drinkable), then waste it on our lawns. Lawns don’t need heavily treated, drinkable water!  Jerry Jeff (the country artist) told me recently that he has a house in Belize where he has a holding tank under the house the same size as the foundation. This tank catches the rain water that is then used to flush the toilets and irrigate the landscape. What is the point in heavily treating water that you flush down the toilet or use for irrigation? Not only that, but the chlorine used to treat water is not optimum for plant health anyway.  This is simply one thing most Americans just don’t think about.

An idea worth considering

So back to fake grass.   It’s just another option for the Austin area.   Maybe it’s not for you, but maybe it is.  It is expensive to install, but once installed it looks real!   And it lasts, too.  For up to 10 years or more before it starts to fade.  We are getting better at making it, and it’s a more viable option than ever before.  As we seem to be getting worse and worse droughts here all the time, andLakeTravisjust gets lower and lower, maybe we should be getting more creative with our options.  I’m just saying…

Improper pruning and its effects

Topping? Lion-tailing?  What do these terms mean? 

Of the damage that can be done by improper pruning, topping and lion-tailing are certainly two of the worst things that can be done to tree.

Why you shouldn’t top your trees

Topping involves removing the tops of the limbs and leaving huge, ‘stubbed off’ limbs and nothing else. A fellow arborist I worked with over 15 years ago likened it to a person having their arms and legs cut off.  More often than not, it kills a tree outright.  If the tree does survive, it has to tap into all of its energy reserves to re-grow multiple limbs from each cut. Unfortunately, as these new long skinny limbs re-grow around the outside of each large wound, the center of the wound then begins to rot slowly over time.  While the weakly attached re-growth often eventually breaks at the area of attachment, the actual limb itself rots from the center causing even weaker and more dangerous limbs over time.

Topping typically kills slow growing trees, such as oaks, right away. Unfortunately, these are the trees that are the best at compartmentalizing rot and have the strongest wood.   Also, topping usually kills excurrent trees such as pines or bald cypress (that have a pyramidal shape and one dominant, central leader), outright.  Survivability after topping is much higher in faster growing, softer wooded trees such as maples or ash trees.  Unfortunately, these are the very trees that rot the fastest because they are poor at compartmentalizing rot.  These softer wooded trees quickly become hazardous after topping.

Heading is like topping, but is done to an individual branch.  Heading back a limb has the same effect as topping.  If the limb gets enough sunlight, it re-sprouts many new branches from the cut.  These branches are also weakly attached, and unsightly.  Branches that are pruned properly are much less likely to re-sprout.  If limbs that are in full sun are headed back into the canopy and are shaded, they typically die.

Why lion-tailing should never be done

Lion-tailing, or ‘poodle-tailing’ is done by stripping branches of all their lateral limbs, except for the branches at the end of the limb. This causes the limbs to look like a lion’s tail, or a Dr. Seuss truffula tree, for example.  This is extremely bad for the tree, and causes the limbs to eventually break off due to the excessive weight at the very end of the branch. This also has a weakening effect over time.  Limbs have many living ‘lateral’ limbs along their length.  These lateral limbs have the effect of strengthening the limb over time as they expand, but also have the effect of increasing the limb diameter at that point along the limb, increasing taper by increasing the limbs diameter at that point along the branch.   Limbs with little to no taper are always very weak, and much more prone to failure.  Add to that the effect of weighting the branches only at the ends, and we have a seriously unsafe situation that gets much worse over time.

Certain trees, such as maples, are more prone to re-sprouting.  Oaks, for example, often do not re-sprout.  Certain trees have more inner leaves than others.  Oaks, for example have much less interior leaf growth than maples, ash or elms.   This contributes to the trees ability to re-grow leaves in the center after limb loss.  This is of course taken into consideration when pruning each species.

The costs of improper pruning

When it comes to pruning, you can pay a great deal of money to have your trees destroyed.  I have seen it happen before many times.  Years ago my neighbor paid $2400.00 to have his four ash trees lion-tailed.  For five years after he had it done, limbs were continuously breaking and hanging down in the canopy, causing hazardous situations continually.  Over-thinning or topping trees leave you with an additional expense to have them removed when they die.  Then you have the expense of re-planting as well.

I still see these types of poor pruning today.  Although it is not as prevalent as it was years ago, it does still happen.  Bad pruning cuts are a daily occurrence with poorly trained pruning crews. A ‘flush cut’ that cuts off the branch collar cannot be corrected, and may never heal, leading to rot and even tree failure in the future.  Stub cuts, although they can be corrected, are unsightly and can also lead to decay and infection when left.

It is better to get a seasoned certified arborist out to your property to have it done properly the first time Trees can add up to 20 percent to your property value.  There is simply no substitute to hiring the right person when it comes to your valuable trees.  Don’t cut corners.  Often you will even pay the same for bad pruning work, as you would for a quality job.  Call us for a free estimate!

About dead limbs in live oaks

Are there smaller diameter dead limbs throughout the canopy of your live oak?

In a drought, the live oaks, as with most trees are also experiencing stress.   The good news is that live oaks are extremely drought tolerant.  They are resilient and can handle long periods with very little water.  Very few diseases affect live oaks, and those that do (oak wit aside) are often not fatal.

It is important to note that live oaks form dead wood in the inner canopy naturally over time.  This ‘interior’ dead wood is normal and forms because the interior limbs get less sunlight as the outer canopy grows and thickens over time, causing them to drop their leaves and ‘shed’ these branches.  The scientific name for this branch shedding is cladoptosis.

Occasionally, live oaks lose previously healthy limbs in the canopy.  These can be caused by physical damage such as wind damage or vehicle damage, or in rare occasions they can be disease related.

When trees are weak from stress, they are more susceptible to disease.  One of the diseases that live oaks get more frequently during drought years is a fungus called twig blight, Cryptocline cinerescens.   It is not widespread in theAustin area, but when it does happen, it can be scary to the homeowner.   Since most local arborists are not familiar with this disease, it is often misdiagnosed.

I was first introduced to this disease 20 years ago inNorthern California, where it is much more prevalent.   The disease is characterized by many dead and dying limbs of smaller diameter, scattered throughout the live oak canopy, usually but not always fairly evenly distributed.

This disease is rarely fatal.  Most of the time, it is just responsible for the death of specific smaller limbs throughout the canopy which then can be pruned out past the transition zone into the healthy wood.  After that, we usually spray the tree with a fungicide to address re-infestation.  As with all diseases, initial and correct diagnosis is the key.

Why do Bradford pears split?

Maintaining Bradford pears in the United States is a multi-million dollar per year industry. When Bradfords were more widely planted, billions or dollars were spent maintaining, bolting, cabling and bracing them. Cities are and have been moving away from Bradford pears for years, and are replacing them with less problematic, more easily maintained and longer lived species.

Every time we have a storm of any intensity, I ALWAYS get a phone call for a split Bradford pear. Upon inspection, the question always arises as to whether or not to remove the broken limb(s) or, in cases with extreme tree/trunk damage, remove the whole tree. Often the damage it too severe or the aesthetics of the tree is so compromised the homeowner wants to remove and replace.

Another problem with Bradford pears is that they do not live very long. A life expectancy in the range of 18-25 years is typical, depending on the site. As for the size, people are often surprised at their canopy spread as the trees approach maturity. When they start getting large, the limbs have a tendency to have very few upright limbs, as most of the limbs pull down as they thicken up. This leaves the center sparse and aesthetically displeasing to many people.

The reason Bradford pears split, is quite simple. Firstly, they have numerous limbs that all originate from the same point on the stem. These limbs all have weak, acutely angled crotches to begin with, all with included bark. Included bark is bark that forms on the inside of the branch unions, and where it forms there is no wood to wood connection. Additionally, as these limbs expand in diameter they put pressure against one another. As these limbs are already weakly connected due to the included bark, the additional end weight exacerbates failure potential. Add to this weak dry wood, due to drought conditions, or wind and added water weight in summer storms, and you have a recipe for disaster.

I have had customers in tears before due to Bradford pear failures from summer storms. If it’s the only front yard tree you have, it can be quite devastating to the landscape when it fails. They are beautiful trees in the springtime. They explode with striking white flowers, and they are relatively bullet-proof with respect to most diseases. Also, there is no messy fruit to deal with.

So, are there any substitutes for Bradford pears? Yes! There is the aristocrat pear, Pyrus calleryana, ‘Aristocrat’, 25-45 feet tall at maturity and considered a much better species, with a dominant trunk and more open form. Why reputable tree nurseries still sell Bradford pears is beyond me. There are of course many other species to consider as well, such as crepe myrtles, non-flowering species like Chinese pistache trees, and many others.

If you do have a Bradford pear, it is not necessarily the end of the world. If the tree is maintained and thinned out regularly, and cabled in extreme cases, it can give the homeowner many years of shade and spring color.

When is the best time of year to prune my live oaks?

One of the most frequently asked questions I get is: when is the best time to prune my live oaks? Is there a “correct” or “better” time? Many people believe the spring is a bad time, or summer is a bad time. Are they right? Are they wrong?

The bottom line is that there’s a lot of bad, unsubstantiated misinformation circulating. To preface my answer, I am a professional, certified arborist. I graduated from Virginia Tech with a degree in forest management and I have been pruning and caring for trees for more than 18 years since I graduated, including the last 12 years in the Austin area as the owner operator of Central Texas Tree Care. We pride ourselves on solid, scientifically based, high end tree care. We have a stellar reputation from Georgetown to Buda.

As I drive to customers, I constantly encounter community signs that say “do not prune your oaks from January to June.” Local radio stations and even TV stations interviewing “experts” tell people the same thing. A search on the Internet will find articles repeating the same information. Do all Central Texas tree care companies hang up their pruning equipment for half of the year? Should they?

The answer is a resounding NO! If an oak tree needs to be pruned, it should be. The simplest and easiest way to explain this is that if an oak tree has limbs rubbing against the roof or hitting cars in the driveway, or if limbs are being broken by large vehicles driving down the street, then the tree has cracked, broken or rubbing limbs causing constant sap flow. If these broken/rubbing limbs (including crossing limbs in the canopy of the tree) are not corrected, the tree is at constant risk of infection.

Once an oak tree is properly pruned, with cuts being sealed off to eliminate sap flow, then the tree is much less likely to get infected. In fact, in all my years pruning trees in Central Texas, not only has our company NEVER had a healthy tree we pruned get oak wilt, but I have never even heard of an instance where a reputable, scientifically trained tree care company had a tree get infected with oak wilt because they pruned it.

Through my years of hands-on field experience, I have found that improperly maintained live oak trees are usually the trees that get the disease first. Then the fungus spreads through the roots to the healthy live oaks. Improperly maintained Spanish oaks are more likely to contract the disease from the beetles for the same reason.

Additionally, no scientific data exists that says leaving at-risk oak trees unmaintained is a sensible measure for containing oak wilt in Central Texas. In fact, I believe that if we pruned more Central Texas oaks to ISA ANSI-A300 pruning standards we would have less oak wilt, especially in urban areas where trees can be more realistically maintained and pruning companies regulated by municipal laws and regulations.