Certified Arborist /Arbor Vitae Tree Care

Well, it’s that time of year again.  When most arborists are inundated with the question “Is it safe to prune my oaks now?”  Or, “Why are there signs in my neighborhood saying I shouldn’t prune my oaks now?”  These signs are particularly prevalent in northwest Austin.

live oak leaf symptomatic of oak wilt

For more details about oak wilt,  see my dedicated oak wilt page, or go to my previous post on it.  But since it is that time of year, I thought I’d revisit the issue here.

Regarding those signs, you’ll notice most of them say “Do NOT Prune Oaks…”, etc.  Well, the guidelines they were derived from never said “do not prune…”.  They recommended avoiding oak pruning in the spring.  The latest version of those guidelines (on my oak wilt page) indicate what oak pruning can (and actually should) be done year-round. Continue reading →

While tree pruning is probably the most commonly performed tree care service, if done incorrectly it can have severe negative long term impact on tree health and safety.  For a detailed explanation of what correct pruning is and isn’t, see my “Pruning Tips” page.

One quick way to determine if you are dealing with a professional is by the language they use.  Dr. Alex Shigo, the father of modern arboriculture, used to emphatically make this point all the time.  And when it comes to removing branches from trees, professionals refer to this as “pruning”.  “Trimming” is for hair; “sculpting” is for rock.  May seem like a minor point, but this “test” is actually pretty accurate, at least in Austin.   Sculpting in particular is a term used by some yahoos that like to strip all the foliage out of the interior of tree- BAD idea! Again, see my pruning tips page.  Ask to see the work of anyone you’re thinking of hiring.  If the canopy of every tree they prune looks like an umbrella, don’t hire them!!!

Knowing the term “branch collar” can be another indicator of how knowledgeable a tree care provider is or isn’t.  Of course beware of posers who just throw around esoteric terms without having a clue what they mean.  Someone who really knows what a branch collar is can explain it to you in a way that makes sense.  Again, see my “Pruning tips” page.  ONLY hire tree care companies that make ONLY branch collar cuts.

The pictures below show the proper removal of the typical branch at its collar.  However, it is critical to understand that the shape and angle of the branch affect the final cut.   Not all branch collar cuts look exactly like the one below right.  The point is that most cuts that are either flush against the trunk or which leave a “stub” are incorrect.  The flush ones can be quite injurious.

proper branch removal Fig. 1

Proper branch removal Fig. 2

Ball moss and mistletoe are two common tree pests in Central Texas,

ball moss

frequently removed when tree pruning.  Here is some info on what these plants are, how they are harmful and how they can be treated.

Ball moss is not really a moss, but an epiphyte or air plant, meaning it’s roots are exposed to the air.  It is in the bromeliad family, and so is related to pineapples, believe it or not.  While the majority of experts believe it is not harmful, because it is believed to receive its nutrition entirely through air and rain, some arborists including me believe that in large quantities ball moss definitely has a negative impact on trees.  This is due to its shading out buds and young leaves.  There is definitely a major impact when we have ice storms, as the greatly increased surface area causes much more breakage on limbs coated with ball moss. Continue reading →

Red oak showing iron deficiency common in alkaline soils

Tree fertilization can be performed in numerous ways and goes by a number of names.  Sometimes called “deep root feeding”, this term is incorrect for a couple of reasons, and is a good clue that someone calling it that has a poor understanding of tree care. Continue reading →

Remaining stub from fallen limb showing internal decay

As mentioned on my Pruning Tips page, tree safety is one of the two most important aspects of tree care.  And a critical component of tree safety is knowing how to assess potentially hazardous trees or limbs.  Being able to detect decay is a major part of that.

A few things to understand right off the top about this subject;  tree decay is caused by numerous species of fungi, and often the loss of wood strength they cause is not visible externally.  That means that no intelligent arborist is going to guarantee the safety of any tree or limb with 100% certainty. Continue reading →

The last two years have turned out to be some of the toughest of the last half-century on our central Texas trees.  Last year’s drought outright killed an unusually high number.  Ironically, many that have survived, especially pecans, are now breaking apart due to drought-weakened wood supporting (or more accurately, not supporting) excessively heavy branch tips and nut crops due to recent rains.  For every tree service I have spoken to, 2012 has been the year of dead tree and broken branch removal.

But now what’s really making the phone ring are calls about “tree sap” making every thing sticky.  These calls are mostly about pecan trees, but people with crepe myrtles and oaks are calling too.  But it is not tree sap that is making a sticky mess of everything.  It is a variety of insects. Continue reading →

Unless you were specifically looking for me, you probably came across this site while searching for tree trimming, pruning, arborist, or some other tag words, and along the way have seen or may see sites for dozens of so-called arborists.  My oh my, how ever does one choose?

There are lots of variables that can help you find a competent person to provide tree care for you, but I’ll start with the word “arborist”.  It may surprise you to know that unlike “doctor” or “lawyer”, there isn’t any sanctified definition of this title, or the use of it- anyone with a chainsaw and a ladder can call his or herself one.  So that can be a clue right there- anyone stating or implying that they are “licensed” by the state (of Texas) to perform tree care is, as politicians love to say, being disingenuous.

Yet there is such a thing as a Certified Arborist.  The certifying organization is the International Society of Arboriculture.  They have had a national certification program in place since around 1991.  In Texas, the first I.S.A. Certified Arborist exam was given in 1992.   I was among the small number who took and passed that test, and I have maintained my certification ever since.  Renewal requires acquiring only 30 CEU’s over a three year period;  I have totalled over 700.  In fact, I am hired by ISA and the Texas Forest Service and other agencies to teach  many of these CEU classes.

It is important to remember that passing the Certified Arborist exam does not make one the be-all-end-all of tree knowledge.  It is a test of the most basic knowledge one needs for tree care, and the prerequisites for being able to take the exam could include having planted flowers for a living (not that anything is wrong with that).  So there are some very smart people with pretty much no tree care experience who have passed the exam, and a lot of not-so-smart ones with lots of experience doing tree care really poorly.  So don’t let this be your only qualifier.

It is also important to know that most tree services in Austin do not have Certified Arborists actually performing the work they sell.  Often a company has a Certified Arborist as its owner,  salesperson or foreman, and the people actually doing the work were digging ditches the month before (not that anything is wrong with that).  You’re better off hiring a company in which Certified Arborists actually do the work, like mine.   And don’t be confused by the Certified Tree Worker designation (which I also have).  This certification  focuses more on basic climbing skills, not arboricultural knowledge.  While it is admirable for a company to certify its employees, it is by no means an assurance that the consumer will receive quality work.

It’s important to make sure that persons working on your property have an adequate amount of quality experience to back up their certification.  I recommend a minimum of 20 years for the owner or manager of your account and 7 years for those actually doing the work.  Yes, there are many with less experience that are quite competent, but the chances of getting an incompetent one (or worse) are higher with less experience.  However, there are also unfortunately many with more experience who are incompetent or even outright dishonest.

Insurance is another factor to consider.  All competent tree services in Austin carry appropriate insurance.  This means general liability insurance, personal injury insurance for owners and workers compensation for employees.  It may surprise you to know that none of these are required by law in the state of Texas.  Just to be clear, remember that having these insurances is not a guarantee of quality work.

But any company that does carry insurance will be happy to show you proof.  Just remember, you should verify that the policy is in force.  We had a case in Austin some years ago where the city hired a tree company that actually provided a completely bogus insurance certificate to the city, which the city never verified until after the work was done.  Despite this and the fact that the work did not meet industry standards, the company was still paid.  Your tax dollars at work…

Be especially wary of memberships.   My personal experience is that the more prominently a company advertises memberships,  in the Better Business Bureau for example, the less likely they are to be a quality operation.  The BBB has absolutely no enforcement power, and has little incentive to punish businesses who pay a fee to be members.  Likewise, memberships in tree associations like I.S.A. or T.C.I.A., without accompanying certifications or accreditation, mean nothing more than that someone paid an annual fee to use the group’s logo.  I have seen several tree companies in Austin over the years advertise membership in organizations that don’t even exist!

Finally, check the arborist’s work.  You can become familiar with what proper tree care is by reading about pruning on my website, and ask for and verify references.  Obviously, a company isn’t going to tell you about people who have been dissatisfied with their work, and internet referral sites are laden with misinformation (both pro and con), but if you take the time to become familiar with what a properly pruned tree should look like (it’s not rocket science), you can look at a few dozen trees and tell whether they have been pruned well or not.

Or just make it easy on yourself.  Hire Guy LeBlanc!

Guy LeBlanc

Warm weather will soon be returning to central Texas, which means folks here will soon be thinking about pruning their trees and other aspects of tree care.  A common question that comes up now is, “What about oak wilt?”  For years, it has been recommended by government agencies to avoid pruning oaks in the spring because of a perceived increase in the risk of getting oak wilt.  What is the reality of pruning oaks while minimizing the risk of this deadly fungus?

About a year ago, I chaired a group of arborists from the Texas chapter of the International Society of Arboriculture, the Texas Forest Service, and Texas AgriLife Extension Service which clarified the existing guidelines.  This was to explain to the public that certain kinds of pruning can be done year-round on oaks.  This would include removing dead branches, and branches at risk of being hit by vehicles over streets, and those rubbing against buildings or other branches within the canopy.  For details on this, see my oak wilt page.  You can also see a Central Texas Gardener video of me explaining oak pruning and oak wilt on YouTube.  To read the statement in its entirety, do a web search for “pruning guidelines for prevention of oak wilt in Texas”  and “Guy LeBlanc”.

oak wilt symptoms

Oak wilt has been in the news locally for so long (in Austin it almost created hysteria in the early 80’s) that I sometimes forget that most homeowners don’t really know much about it.  In brief, it is caused by a fungus very closely related to the Dutch Elm disease fungus which many folks from northern U.S. are all too familiar with.  It only affects oaks (and tanoaks).  The disease spreads in two primary ways.  The majority of the spread of the disease (95% of it according to one researcher) occurs underground due to the propensity of live oaks to form grafts (actual vascular connections) between the roots of different trees.  Live oaks also occur in groups called motts, which means that all of the trees in the group have formed from root sprouts.  Motts are also therefore interconnected and the disease spreads quite readily through them.

The disease can also spread above ground, creating new infection centers.  This occurs when vectors (in this case a beetle called the nitidulid is most likely the culprit) visit the fungal spore patches (called mats) on infected trees and then carry those spores to fresh open wounds on healthy trees.  In Texas these mats only form on red oaks, never on live oaks, so it is important to remove dead red oaks immediately- in fact in Austin, there is an ordinance requiring any property owner to do so.

It is believed that the nitidulid is attracted to both the odor of the mats, which have a fruity-licious smell, and the odor of fresh sap from new wounds.  The highest levels of this insect population and the creation of fungal mats coincide only when weather conditions are just right, which is usually in the spring.  This is why government agencies have recommended avoiding pruning in the spring.

However, we also know that very often in spring the weather conditions are not conducive to the development of the fungal spores (too hot and/or dry).  No spores = no above ground spread.  Or it can be too cold for the insects to be active (last year it was in the 20’s for 3 days at the end of Feb).  We also know that painting wounds provides a nearly total barrier against spore invasion.  There is no published scientific study in which painted wounds contracted oak wilt (one study in 2007 seemed to contradict this, but it was found that the trees were becoming infected underground).  We also know that dead tissue cannot be an invasion point for the spores, so removing completely dead branches never exposes a tree to oak wilt; technically, dead tissue doesn’t even have to be painted, however, I usually paint it just in case some live tissue is present on part of the wound face.

The bottom line is that while oak wilt is often fatal, the actual risk of contracting it through open wounds, even in the spring, is minimal.  If it wasn’t we probably wouldn’t have any oaks left, as wind, hail and animals such as squirrels and birds cause extensive wounding, often in the spring.  And this risk can be actually be reduced if the pruning is done by a competent professional – which is of course the only type of person you would ever let touch your trees!