Certified Arborist /Arbor Vitae Tree Care

I’m definitely seeing an abnormal amount of live oaks declining or outright dying this fall.  More so than even last year, when we were much drier. So what’s the cause? Many homeowners are contacting me wondering if they have oak wilt. This is the usual concern whenever a homeowner sees an oak on their property that does not look normal. The good news for these folks is that so far none of the ones I seen this fall that look like this have oak wilt.  Here are some pictures of the primary way I am seeing these trees present:

Dying Live Oak – Photo A

Dying Live Oak – Photo B

Healthy Cambium – Photo C

Notice that in both photos, all of the remaining leaves are brown.  I expect most trees in this condition to die, if they’re not already dead.  A good way to test is to scrape the bark on some of the smaller branches where the bark is thin.  If the tissue immediately under the outer bark (the cambium area) is a bright greenish color (Photo C) that part of the tree is alive and healthy.  This does not mean the entire branch is healthy, just the branch up to the point where you test the tissue. It could be dead beyond that (towards the tips), or other branches in the canopy could be dead.  So testing in several spots is necessary for a fuller assessment.  If the cambium tissue is brown, that part of the tree is dead.  If it is a pale yellow, then it’s alive but doing poorly, and most likely will die.  Be aware that these inner bark colors are those you’d find on small live oak branches.  A greenish cambium region is common on many other species but not all.  And on larger live oak branches, a healthy inner bark will be a rusty reddish color.

There are actually still some green leaves on the tree in Photo B, but they are on the back side, low on the canopy, and not visible in the photo.  This is another common way in which stressed trees are presenting this fall; some sections of the canopy are completely brown, and others are full of healthy leaves. Continue reading →

The beloved leaning pecan at Barton Springs Pool

The pecan tree that leans heavily over the Barton Springs Pool is scheduled for removal.  As an arborist who has fought for the preservation of trees in Austin for over 40 years, I  unfortunately must agree, it’s time to say goodbye. This iconic tree has been at high risk of failing for decades, its heavy lean first documented in historical photos from the 30’s.  The city of Austin has done everything possible to physically support the tree, from using tar, concrete and rebar to fill the massive cavity in its trunk (where decay created a hollow large enough for a man to easily fit inside of it), to installing steel support posts, to anchoring support ropes to nearby structures.  For decades it has been poked, prodded and even internally examined with high tech sonar equipment. Realizing its days were numbered, they even planted a replacement tree next to it in the 70’s.

The question on everyone’s mind of course is, “Can’t it be saved?” Continue reading →

Texas was hammered again by severe winter weather on February 1^st and 2^nd  2023.   Unlike the more statewide “Snowmageddon” of 2021, this time the tree damage was not as widespread.  Based on state disaster declarations, the worst of the damage occurred in 23 counties, including all of central Texas and extending intermittently northeast to the OK-AR border.  In 2021, damage was mostly from freeze rather than breakage. This time the amount of limb and tree breakage was far worse in the Austin area, necessitating a more urgent clean-up response, versus the more gradual clean-up that occurred in 2021 as we waited to see what trees had survived.

Due to temps hovering right around freezing for two days, with a slow constant drizzle, central Texas had ice thicknesses up to three quarters of an inch.  Countless limbs snapped throughout the day on February 1, and even more failed on the second as more ice accumulated.  Although weather persons in Austin referred to it as the “worst ice storm since 2007” this oft-made statement left many a seasoned arborist around here scratching their heads.  In 43 years of doing tree work in central Texas, I’ve never seen ice storm damage that came close.

According to Texas electric utility reps, half an inch of ice is right around the breaking point, literally, for trees. This of course depends on the species, and evergreens like  live oak, Ashe juniper and TX mountain laurel were the worst hit in Central Texas.  Based on my observations, cedar elm was the hardest hit deciduous species, with Arizona ash, red oak and crepe myrtle damage also common.  Strangely, “self-pruning” pecans (don’t you love that term?) barely lost a twig, from what I saw.

Most of my clients rarely see storm damage, whether it be from ice or wind.  This is of course because well maintained trees statistically experience far less storm damage. However, the severity of this event was exceptional in that even perfectly managed trees suffered extensive damage. My observations were that larger broken limbs (bigger than about 7 inches diameter) almost always had some decay which was almost always visibly associated with an old pruning wound.  So it is vital to remember that pruning does cause injury, and especially if it is not done properly, that injury can lead to decay and failure years later.

So how should ice-damaged trees be cared for? Continue reading →

This year’s drought has been quite reminiscent of the ones in 2011, except this one started earlier (and thus far seems to have ended earlier). Unlike the 90 plus days of 100 plus degree heat in 2011, this year’s number of super hot days was much lower (again, thus far), but because it started earlier, many trees still struggled or died. In fact, this was the first spring in my business’ 40 year history that I was calling my clients to recommend that they irrigate their trees.

Yet the good news is that probably because we had far fewer hot days, we have not seen near the tree losses state-wide that we did in  2011, when losses were in the millions. There were areas around Brownwood (aptly named after 2011) that had acres and acres of trees die (many of them junipers). Here in Austin, it seemed as if we lost 5 or 10% of the pecan trees on the east side, and even live oaks, the sturdiest tree in the forest, suffered significant losses, especially on high grounds. The area uphill from Barton Springs Pool, near the polo fields (better known as the overflow parking dustbowl) lost quite a few live oaks. So the losses were city- and species-wide.

Dieback in pecan from drought stress

The dieback shown here is typical of what is seen with drought stress.  It may look very familiar to those who experienced the frozen hell imposed on us by Governor Abbott and his PUC cronies on Valentines Day 2021 (yeah, I said it-  this is my damn blog!). It is not unusual for plants to have a similar reaction to very different problems; overwatering and underwatering can both make a houseplant’s leaves turn yellow. With drought though, there’s usually some browning on the edges of the leaves first. Continue reading →

As I write this, central Texas is experiencing its worst winter weather event in decades (so what else can I do but write?).  Having done tree work here for 40 years now, I’ve seen quite a few cold weather episodes in Austin.  There was a five day stretch in December of ’83 where we never got out of the 20’s.  Many palms and most tallow trees around Austin froze to death that year, but there wasn’t any precipitation, so breakage from snow and ice wasn’t an issue.

Ice damage to live oak central Texas

A couple years later  (’85) we had two events a couple weeks apart that totaled about 7 inches of snow but also pretty bad icing, and we got some breakage with that.  In ’89 we got the coldest blast I can remember, down to about 4F, but it was a quick dip, and I don’t remember a lot of breakage with that one.  (Am I sounding like an old man yet??)  Over my four decades here, I’d say I’ve seen at least 8 ice events bad enough to result in at least some breakage.  So they happen more often than you might think.

Okay, so what can you do about it?  Continue reading →

Oak wilt continues to be an issue throughout Austin, central Texas and much of the central part of the U.S.  This often fatal disease is spread by a fungal organism known as Bretziella fagacearum (previously Ceratocystis f., but scientists often change organism names just to mess with us arborists!)  Other than the name change, there’s little new about this disease, other than some news about DNA testing, but the likelihood of fast, accurate field test kits being available anytime soon is small.  For more details on oak wilt, see my previous posts and my Oak Wilt Page.

At this time of year, whether you should or shouldn’t prune your oaks is quite forward in the minds of many neighborhood activists.  You may have seen signs saying not to prune at this time of year.  For years it has been recommended by various government agencies that one should avoid pruning oaks in the “spring”.  The definition of spring has changed quite a bit over the years.

My advice to homeowners is Continue reading →

© 2019  guy leblanc  all rights reserved

Pruning young trees requires an understanding of how trees grow.  Sounds obvious, but in truth many people lack even a basic understanding of this.  There are three key points one needs to know about how trees grow in order to get them off to a healthy start.  Without this knowledge you can make mistakes that could persist for the life of the tree, reducing its aesthetic value, and even possibly leading to catastrophic limb failure years later.

The first thing to understand is Continue reading →

©  2018- 2019 guy leblanc. all rights reserved

Cabling is the use of hardware to support trees or branches that are defective or weak but that the tree owner does not wish to remove. Sometimes weak limbs are retained because removing them would be very stressful on the tree. Cables are also sometimes used to keep healthy limbs from settling lower over time with gravity.

Proper cable installation

Defects could include a cavity or decay, a weak connection between two branches or inadequate branch strength.  It is critical for a property owner to realize that such defects make the risk of limb or tree failure higher, even when cabled, and that complete removal of the weak part is safer than cabling, especially if the consequences of failure are severe.

There are many cabling techniques out there, but only a few meet industry standards, which are fairly detailed.  A few things you can look for to determine if a cable was properly installed include Continue reading →

©  2017-2019 Guy LeBlanc all rights reserved

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, but really should be left to professionals during those springtime months. Continue reading →

© guy leblanc 2015-2019 all rights reserved

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.  Continue reading →