P90901It has been almost a month since one of three small but sculptural and very prominent coast live oaks at work was destabilized by . . . well, children. They were climbing on it, as most good children should do. There were a few of them; and the tree is old and deteriorating. All three of the trees actually grew from the same rotten stump of a tree that was cut down decades ago.

I wrote about it at ‘Six on Saturday – Do Not Sit On Tree‘. The title will make more sense if you read about it.

To salvage the tree, I pruned off as much of the foliar canopy as possible. This eliminated some of the weight that the trunk needs to support, as well as decreased some of the resistance to wind, which exerts leverage against the compromised root system when wind blows. Sawhorses were placed under the trunk, and one of the others, to prevent them from sagging any lower.

Props that were fabricated to be more permanent then the sawhorses were installed last week. They do not actually support or even touch the trunks, but are there to prevent the trunks from sagging any lower. If the trunks start to lean on the props, I will prune a bit more weight off. If that doesn’t work, the props can be moved a bit farther out, where the trunk are higher.

Hopefully, the old root system of the destabilized tree was not so severely damaged that it can not recover. If it does recover, and the trunk is not supported by the new prop, the tree will need to eventually regain stability. It will be a tediously slow process. Because the trees are already so mature and disfigured, the props will likely never be removed, regardless of recovery.

The first picture above show the destabilized tree outfitted with a new prop. The second picture below shows the other tree that was outfitted with a new prop just because it is so likely to become destabilized.



Arborists Are Modern Tree Surgeons

90724thumbThe terminology has certainly changed over the years. Not many of us remember what tree surgeons were, or that there were actually a few different kinds of tree surgeons, who performed very distinct tasks. Tree surgeons are now known as ‘arborists’. Much of what they used to do is done by other types of horticultural professionals. The work that arborists still perform is ‘arboriculture’.

Back when orchards were still common in the Santa Clara Valley, Orange County, and many of the areas of California that are now urban, those who pruned deciduous fruit trees while dormant in winter were known as tree surgeons. Of course, they did other work that the trees needed through the rest of the year, and harvested fruit as well. They might be known as orchardists nowadays.

Tree surgeons also assembled new orchards, as well as individual trees in home gardens. It used to be standard procedure to install the understock of fruit trees in the first winter, and let it grow through the following year. A tree surgeon would return while it was dormant the following winter, to graft desired scions onto it. This is now done by nurserymen in nurseries that sell finished trees.

The tree surgeons who we now know as arborists are, of course, still important. The tree surgery that we now know as arboriculture is the sort or work that other horticultural professionals are not qualified or able to perform. It involves the biggest of trees that are out of reach from the ground, or even from ladders. There are still a few different kinds of arborists, but most must climb trees.

Arboriculture is the horticulture of trees. Arborists are therefore horticulturists of trees. Those who are certified with the International Society of Arboriculture, or ISA, have passed an examination of their arboricultural expertise, and maintain their credential by continued involvement with the educational seminars, classes and workshops of the ISA. Arborist can assess the health, stability and structural integrity of trees, and prescribe and supervise necessary corrective arboricultural procedures.

Horridculture – Tree Removal Permits

P90703There are mixed emotions about tree removal permits that so many municipalities need to issue in order for a ‘heritage’ tree to be cut down legally. Most of us want to believe that in America, we have certain rights to do what we want to on the properties that we own. Obviously, that makes the most sense. However, if it were that simple, many more prominent trees that are collective assets to the larger communities would be removed.
As an arborist who writes the reports needed to procure these permits, I see it both ways. There are many trees that are worth preserving for the Community, and there are probably many more that must be removed for the safety of those who live around them.
I sometimes hear of common homeowners who get fined for removing a tree without a permit, just because they were not aware that it was protected by an ordnance. Most have lived in their homes longer than such ordinances existed. Most planted the tree that they were fined for removing.
Conversely, I also hear about developers who just remove whatever trees get in the way of their developments, and then just pay the necessary fines. It is nothing to them because they make so much money from the development.
The picture above is a site that one of my former employers worked on just before I left my job because it was too morally challenging. You can see that there are no significant trees. The tree crew removed all of them.
I was not aware of it of course. The Home Owners Association did not want to pay for my inspections and reports, or for the permits to remove all the big sycamores in the front gardens there. Nor did they want to replace the removed trees with something more proportionate, as the local municipality would have required. They were not worried about getting caught, since everyone there wanted the trees gone.
Now realistically, I would have had no problem writing reports recommending the removal of all the trees, because they were ridiculously disproportionate to their particular application. You can see how tiny the front gardens are. It was just easier and less expensive to cut the trees down illegally, and then not be required to replace them with trees that would have later died ‘accidentally’ anyway. (The tree crew excelled at that too.)
In the end, it is disgraceful that the trees that were required as a contingency when the site was developed years earlier are now completely gone, and will not be replaced, . . . and that no one seems to care.

Spontaneous Limb Failure Is Real

90605thumbIt sounds like science fiction, but it is not. Every spring and during particular summer weather, limbs can fall from trees without warning, and seemingly for no reason at all. It happens when least expected, while the weather is warm and perhaps humid, but notably without wind. The lack of wind is what makes it so unexpected. It is a phenomenon known simply as spontaneous limb failure.

Those who witness it might think that the arborists they call to clean up the mess will not believe their descriptions of what happened. Yet, arborists are familiar with it. Quite a few species of trees are notorious for it, especially in urban landscapes where they get watered regularly. Most of such trees are either chaparral trees that do not expect much water, or riparian trees that do expect it.

Spontaneous limb failure occurs as warmth accelerates vascular activity, but humidity inhibits evapotranspiration, which is evaporation from the foliage. Accelerated vascular activity increases the weight of the foliage. Inhibition of evapotranspiration limits the ability of the foliage to eliminate some of the excess weight. Limbs break if unable to support the increasing weight of the foliage.

Spontaneous limb failure is not as easy to predict as the more familiar sort of limb failure that is caused by wind. Limbs that get blown down typically exhibit some sort of structural deficiency or disfigurement prior to failure. Some limbs that succumb to spontaneous limb failure do so as well, but most do not. They just happen to be the healthiest and most densely foliated parts of a tree.

Native coast live oak and valley oak are the two most familiar of the chaparral trees that are notorious for spontaneous limb failure. Native cottonwood, willow, box elder and sycamore are riparian trees that are perhaps even more susceptible to spontaneous limb failure. Sweetgum, carob, stone pine and various eucalypti are some of the exotic trees that might drop limbs spontaneously.

In summer, spontaneous limb failure is less likely as growth slows and limbs strengthen.

The Davey Tree

P90317This is no common Douglas fir. It is the ‘Davey Tree’, named after the tree service that so diligently prunes it for clearance from the utility cables above. Yes, I can see as easily as you can how disfigured it is. The plan is to cut it down before it falls apart. At least that is the excuse for cutting it down. It is relatively short an stout, so is likely quite able to support its own weight, regardless of this disfigurement. We really just want it gone because it is so unsightly.
Most who see the Davey Tree are quick to blame the disfigurement on those who prune it for clearance. They do not consider that without such pruning, the utility cables would eventually be ruined and unable to deliver the electricity that so many of us use. Those who prune the trees do what they must to keep the electricity and other utility cables operational. Unfortunately, such work sometimes ruins trees.
As an arborist who sometimes works with other arborists who must perform clearance pruning, I am more likely to blame other landscape professionals. Some landscape designers design landscapes with trees that get too tall or broad within utility easements. Heck, many designers do not even designate where such easements are on the drafts of their landscape plans. Some so-called ‘gardeners’ plant such trees in utility easements with no plan at all. For what they all charge for their services, landscape professionals should know better than to put inappropriate trees into situations where they will eventually need to be mutilated or removed. Not many think that far ahead, or even care.
Anyway, the inappropriate location and disfigurement of the Davey Tree really can not be blamed on anyone. It is a wild tree that grew there from seed.P90317+

Horridculture – Cruel and Unusual Punishment

P90213This landscape is nothing fancy. It is out in front of a fast food establishment on Ocean Street in Santa Cruz. It is low maintenance, and starkly simple. It would be nice if the so-called ‘gardeners’ would cut back the African iris and English lavender a bit better, but they may have left them like this so that they are less likely to get trampled. The colored chips get replenished regularly, and the trash gets harvested quite efficiently. As I said, it is nothing fancy. The only remarkable feature had been this exemplary crape myrtle in the middle.
Only a few weeks ago, it was a perfect small specimen. Even though it is still quite dinky, the main stems were all at good angles, well spaced and aimed in the right directions. None of the stems were crossing over others, damaged or otherwise misshapen.
I can not explain what happened here since then. Are the so-called ‘gardeners’ trying to make more work for themselves by causing problems that will likely need their attention in the future? Do they just hate their work as much as this abuse implies? Is it possible that someone really believes that ‘this’ is somehow beneficial to the victim?
Each of the two fence stakes is sufficient to support a small tree, if such a tree needs it. If a tree, or in this case, a multi-trunked tree, does not need support, it should not be supported. Otherwise, it becomes reliant on the support. Besides that, these are fence stakes that are designed to be somewhat permanent. Now that they are there, they will probably be there forever. So-called ‘gardeners’ who do this sort of thing are not the sort to remove stakes.
The nylon straps are not flexible to accommodate the expansion of the stems they are tied around. If not removed, they will constrict, or ‘girdle’, the growing stems. What exactly are the straps doing anyway? The two closest to the bottom are tied to one stake, and pass the other to reach the respective stems that they are tied to, rather than tied between each of the two stems and the stake that it is closest to.
Someone certainly put a lot of effort into a whole lot of uselessness that will interfere with the healthy development of this formerly exemplary crape myrtle. Yet, with all this effort, no one bothered to prune it, or even so much as deadhead it. Yes, those are deteriorated floral stems from last summer.P90213+

Greenhouse Envy

P90209KIf there were lawns and fences in this neighborhood, the grass would likely seem to be greener on the other side of the fence. In this situation, the greenhouse probably seemed to be more comfortable than being left out in the storm. This tall Douglas fir tree dropped in to find out. It did not go well. What remains can be seen in the middle of the picture above, just to the right of the fallen fir, and in the close up of the picture below.P90209K+
Miraculously, the two coastal redwood trees that caught and guided the fir to a direct hit on the greenhouse also prevented it from destroying the associated house. Well, at least the redwood on the left did. There would have been less damage if the fir had fallen farther to the right. Regardless, a deck was crushed, an eave was destroyed, but the rear wall of the home was barely nudged. Not even the windows there were broken!
Falling debris punched a few holes in the roof, but without structural damage. The patio of the big building to the right was littered with debris that was easily removed. After limbs are removed from the damaged house, much of the carcass of the fallen fir will remain on the forest floor. It decays efficiently here.
Incidentally, this fir was about to be removed. It had been identified as too risky for the neighborhood. Although they are not visible in the pictures, there are a few other homes in the neighborhood. The cabin that I stayed in for more than a week is just beyond where the top of the fir landed. The stovepipe that is visible in the background of the second of my ‘Six on Saturday – Cabin Fever’ pictures from January 5 is the same stove pipe that is visible on the roof of the home that was nearly destroyed by the fallen fir.
(The stove pipe circled by the yellow oval just above the center of the picture above is the same stove pipe circled by the yellow oval just right of the middle of the upper margin of the picture below.)P90209K+++

Six on Saturday: Untimely Death


One of the more unpleasant parts of my work is condemning elderly trees. Redwood and oaks in our region can live for centuries, but none last forever. It is sometimes my job to determine if some of the oldest of oaks have deteriorated to such an extent that they have become unsalvageably dangerous to those around them.

What is worse than that is that there are so many dangerously deteriorated oaks and other trees that collapse before they get removed, and many do so before anyone notices how dangerous they are. Some structural deficiencies and instabilities are concealed to the most thorough of arborists. That is what happened with this big coast live oak, Quercus agrifolia, with a five foot wide trunk, that fell behind Felton Presbyterian Church. I had known for some time that the healthy canopy was heavy and exposed to wind. What I did not know is that the root systems was insufficient to maintain stability when strong wind blew against the healthy canopy while the soil was saturated. The insufficiency of the root system became apparent not only because the tree destabilized, but also because the minimal root system became exposed by the destabilization. There was no evidence of decay or damage within the root system, which are what typically contributes to destabilization.

1. It is amazing that this tree stood for as long as it did with such minimal roots.P90209

2. This is what those minimal roots supported for so long.P90209+

3. Healthy foliar growth on top of the canopy enhanced weight and wind resistance.P90209++

4. Damage was surprisingly minimal.P90209+++

5. This decay within one of the main limbs was a structural deficiency that did not contribute to the destabilization.P90209++++P90209+++++

6. (above) This is the same picture as #5. The red line is at the cross section of where a limb broke or was cut away many years or decades ago. Although the straightness of the zone suggest that it was made by a pruning cut, it is unlikely that the tree was pruned up as high as this section of limb was located, particularly so long ago. As the tree compartmentalized the wound, decay spread inward toward the center from the wound, in a typical pattern that resembles a section of a pie chart, which is marked by the yellow lines. Once it reached the center, decay radiated outward from the center, in a typical circular patter, which is marked by the blue circle. As the center of the trunk rotted and deteriorated, the necrotic zone between it at the original wound continued to rot and deteriorate. By that time this cavity developed, the exterior of the wound had already been compartmentalized by viable wood that did not decay.

This is the link for Six on Saturday, for anyone else who would like to participate:

Horridculture – Disdain For Trees

P90206Okay, we get it; someone really hates trees. That’s fine. Trees are not for everyone. Just cut it down. Put it out of it’s misery. Take away the useless lodgepole stake and strap along with it. Maybe those Canary Island date palms that look like the home of SpongeBob SquarePants in the background will recover from their own form of abuse to compensate for the loss of this seemingly unwanted goldenrain tree.
Apparently, it is not that simple. This goes beyond a dislike of trees, or a mere desire to kill them. This tree seems to have been tortured by someone who enjoys it WAY too much. There were others that were similarly disfigured in this same parking lot in the north of San Jose. They were not pollarded. They were not pruned. There were mutilated, but kept alive for more of the same.
What is worse is that someone was paid for this torture. Property management hired a tree service to ‘prune’ these trees, likely for clearance from lamp poles and parked cars. Was the perpetrator inexperienced, insensitive, or as hateful as the severity of the disfigurement suggests? Well, lets analyze that.
There are plenty of inexperienced people who take jobs in occupations with which they are not familiar. However when the do so, they tend to learn at least the basics about it to avoid doing their work improperly. That obviously did not happen here.
Insensitivity or a lack of concern for the work is possible. However, even someone who does not care about such work is likely to get something about it correct, even if just circumstantially. Well, that did not happen either.
These trees are kept alive because they are more lucrative to the torturer that way. As disfigured as the trees are, they will regenerate new growth that will again need to be pruned for clearance later. Someone who put that much thought into what is being done could have just as easily put forth the effort to do ‘something’ properly in regard to pruning. That is obviously not part of the agenda. The perpetrator really is as disdainful of these trees as the disfigurement indicates.

Arborists Really Know Their Trees

7bd6It is no surprise that there are many different types of physicians within the medical industries. Pediatricians, surgeons, cardiologists, dermatologists, and all sorts of ‘doctors’ are all recognized for their particular medical specialty. Yet, almost all horticultural professionals are known simply as gardeners or landscapers, even though many never work directly in gardens or landscapes.

Production nurserymen grow horticultural commodities (plants). Other nurserymen maintain these commodities while they are marketed. Landscape designers develop the landscapes that many plants inhabit. Only after the involvement of various less familiar horticultural professionals, landscapers install the landscapes, and gardeners maintain them. Somehow, they get too much credit.

Arborists really deserve more credit. They are the physicians of trees, who specialize in arboriculture, which is the horticulture of trees. Much of their work is out of reach to gardeners, and is very distinct from the sort of work that gardeners should be expected to perform. Trees are the most substantial features of a landscape, so really should get the proper attention that they deserve.

The International Society of Arboriculture, or ISA, certifies professional arborists who have passed an examination of their arboricultural expertise, and continue to demonstrate proficiency with discriminating arboricultural standards. Continued involvement with ISA classes, educational seminars and workshops is required to maintain arborist certification. It demands serious dedication.

Besides assessing the health, stability and structural integrity of trees, ISA certified arborists are the most qualified to prescribe any necessary arboricultural procedures, and to direct those who perform these necessary procedures. Most local municipalities require a report from an ISA certified arborist to accompany an application for a permit to remove any protected ‘heritage’ tree.

The website of the ISA, at, Is an excellent resource for finding certified arborists, and the tree service businesses with which they are affiliated. Arborists can be found by name directly, or regionally by ZIP code or city. The website is also a great resource for information about proper arboriculture and trees, and can help those who are not arborists with selection of trees.