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.


Fireplaces Are A Rare Luxury

51028thumbThere are fewer fireplaces after every significant earthquake. Removal of a damaged chimney is probably more practical than repair, particularly if the fireplace does not get much use anyway. Wood stoves sometimes get removed simply because they are in the way. Modern building codes forbid their return once they are gone, and also forbid them in new construction.

The few surviving fireplaces and wood stoves do not get used as regularly as they used to. It seems that no one is around the home long enough to tend to a fire. Orchards that provided so much affordable firewood as they were being removed for urban development are gone now. The outskirts of town, where trees and woodlots might be found, are now more than a short drive away.

Firewood can still be purchased from tree service businesses that must dispose of the wood that their work generates. Because such firewood is a byproduct of urban forestry, it is an unpredictable mix of all sorts of urban trees, and must be procured early in the year to be seasoned by autumn and winter. It is now much too late to purchase green firewood for this winter.

Almost all types of urban firewood are comparable to more traditional types. A few types deposit more residue in chimneys, so that chimneys need to be cleaned more frequently. Firewood from woodlots can be surprisingly more expensive; but it burns cleaner, and is already seasoned. Many woodlots would be pleased to deliver firewood that is ready to burn now.

Firewood is perishable, so only slightly more than enough for one year should be procured annually. Any leftovers can rot if left out in the weather too long. Firewood last longer in a shed or garage, but takes up too much space, and can be attractive to rodents.

Synthetic logs from the supermarket happen to be more efficient than real wood, and do not need to be seasoned. A single log burns longer and cleaner than a few real logs, and produces as much heat. However, they are individually very expensive, and are just not the same as real firewood.


P81208KKThe tufts of small branches that so often develop where limbs were pruned from the trunks of a coast live oaks are sometimes referred to as ‘tumbleweeds’. They are about the same size as an average tumbleweed. By the time the get any larger, most of the smaller stems have subordinated and died out, leaving only a few more defined dominant stems, which will continue the process until even fewer or a single new branch dominates. Such tumbleweeds, as well as stems that originated from such growth, are weakly attached to the main trunks. They often get pruned off for the same reason that the limbs that were there before got pruned off, or because they are expected to be weakly attached. If they remain long enough, they can of course develop into new limbs.

Tufts of the same sort of growth on sycamores or other deciduous trees are known more simply as . . . ‘tufts’ I bet you didn’t see that coming. They can get much bigger than tumbleweeds before they develop much distinction between the dominant and subordinate growth. Because tuft growth is innately vigorous, the leaves are bigger and coarser. Then, when the rest of the deciduous trees that produce them defoliate in autumn, the tufts retain their green foliage until it gets ruined by frost.

This big sycamore dropped its top over summer. The tufts developed on the big trunks that became exposed to sunlight by the loss of the upper canopy above. The tree will naturally try to replace its top, but will also naturally be even more disfigured and structurally deficient than it already was. As the tufts develop into limbs, and the limbs get heavy with foliage, they will be very likely to break away and fall. As unpleasant as all that sounds, it is quite natural for such a mature sycamore who is so old that he just doesn’t care who gets offended anymore.

Arborists Are Very Specialized Horticulturists

81205thumbThe first storm of the year has a way of reminding us if our trees need attention. Whether then need to be worked on this year or not, we tend to notice how they blow in the wind, or if they are full of dead and deteriorating debris that falls into the garden or onto the roof. As deciduous trees defoliate, they are less likely to be damaged by wind, but their structural deficiencies become visible.
This is when some of us will contact arborists to inspect and perform necessary arboricultural procedures for trees that have grown to big for us to maintain. We do not want trees to be damaged by the wind. Nor do we want them dropping limbs or falling onto whatever is within their reach. Those that are biggest and most beyond our reach have the most potential to cause major damage.
Arborists are horticulturists who specialize in the horticulture of trees, which is known as arboriculture. They assess the healthy, stability and structural integrity of trees, then prescribe necessary corrective arboricultural procedures, and if necessary, prescribe the best time for such procedures. Most arborists work with a tree service that is equipped to perform the prescribed procedures.
Arborists who are certified by 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. More information about the ISA, local certified arborists and even arboriculture, can be found at the website
As mentioned earlier, arboriculture is specialized horticulture of trees. It is not something that gardeners should be expected to perform; particularly mow, blow and go gardeners who are not even proficient with simple gardening. Many arborists can concur that unqualified gardeners sometimes kill trees, and cause much of the damage to trees that arborists must later correct. Besides, arboriculture is the sort of work that can be very dangerous to those who lack training, experience or the necessary equipment.



By modern standards, the public schools that I attended in the early 1970s would be considered to be bleak and primitive. The building were utilitarian and simple, from about twenty years earlier. The landscaping was comparably simple, with a big lawn and proportionately big shade trees. A screen of alternating Monterey pine and Monterey cypress was hedged on the southern half of the eastern boundary of the schoolyard. The only deviants to the simplicity were a few significantly older trees on the northern half of the eastern boundary of the school yard. There were two coastal redwoods, a Canary Island date palm, a cedar, and a spruce of some sort. They were all quite mature, and were likely remnants from an old farmhouse that was there before. Perhaps they wanted us to be aware that everything changes.
On the way to kindergarten, back when children were allowed to walk to school, I weaseled my way underneath the first Monterey pine and Monterey cypress on the southern end of the fence line, and fell asleep. I do not remember how long I stayed there, but it was long enough to get in serious trouble with my very worried kindergarten teacher. After that, I could only visit those two trees in passing, and perhaps stop only briefly to smell the foliage or shake some of the rain away.
Nearly four decades later, but only a few years ago, I was assigned the grim task of composing the arborist report that would justify the issuance of a permit to remove that same Monterey pine, which was the last that remained of the hedged trees that I remember. I did not know that when I went to the site. I was just told that it was a ‘pine’.
Visiting the old school was not a pleasant experience. The entire site was surrounded with a prison like fence and saran screens to obscure the view inside and out. There were no open gates. I needed to be escorted to the tree by a professional chaperone. Much of the schoolyard had been very synthetically landscaped with microtrees and pretty flowering shrubbery that was intended to impress parents rather than appeal to children. It is bad enough that there are no orchards or open spaces remaining in the region, but it is worse that children are deprived of the open lawns and trees and natural spaces that my generation had taken for granted on the grounds of our school. Are children even allowed to climb trees anymore? Do they know what dirt is? Can they observe a chrysalis split open to reveal a new butterfly before the gardeners shear the shrubbery and take the learning experience away? It was saddening.
Once I realized that the tree that I was expected to condemn was my old friend, I asked the chaperone, who seemed to know a bit about facilities at the site, why anyone would want the now mature tree to be removed. I knew that it had been mutilated while young, but was impressed with how it somehow recovered and developed a well structured trunk. I thought that perhaps someone noticed something that I was missing in my inspection. People who are not arborists are sometimes alarmed by something that is perfectly normal for a tree, such as furrowed bark, or slight seasonal foliar discoloration.
The chaperone explained that the tree needed to be removed simply because it did not conform to the style of the rest of the landscape. I waited for the rest of the answer, but that was it. The tree did not conform.
Nothing gave me more pleasure than to explain that after my evaluation of the health, stability and structural integrity of the subject, I could find no justification for removal.
I was dismissed.
Yes, it was worth it.
However, I knew that for the right price, another arborist would be pleased to condemn the tree. The picture of what remains suggests that the arborist who did so was not even professional enough to get his crew to finish the job. How does this dead stump conform to the rest of the landscape?
Those old trees, the redwoods, palm, cedar and spruce, were right. Everything changes.
The Monterey pine that would not conform is gone now, but it was right too.

High Fashion

P80404This exquisite yet elegantly simple persimmon orange cravat is to die for! See how distinguishing it is for the Umbellularia californica sporting it! The brilliant color is so appropriate for a tree that needs to stand out in a crowd! How else would the arborists coming to cut it down find it? Yes, it is to die for!

This sort of high fashion is not normally so high. Trees that are tagged by surveyors are typically more discretely tagged with spray paint down near the ground. We just used this orange tape because we were only hastily marking a few or our own trees for removal, and nothing else.

The problem with tape in other situations is that it can be removed and applied to another tree. One of my colleagues sent his crew to cut down a street tree downtown that had been marked with orange tape, only to find later that the wrong tree had been cut down. The client had procured a permit for the tree that the arborist had tied the tape onto, but not another tree next to it that he wanted removed also. After the arborist marked the tree to be removed with tape and left, the client removed the tape, and tied it onto the tree that was to be preserved. Of course, the crew cut down the tree with the orange tape. The sleazy client did not want to pay for the removal because the wrong tree had been cut down, and then hired another tree service to legally remove the tree for which the removal permit had been issued, while leaving the first arborist liable for cutting down a protected tree without a permit. Fortunately, a neighboring merchant knew what the client was up to, saw him move the tape, and reported the incident to the responding code enforcement agents. The arborist got paid. The client got two huge fines; one for removing the tree without a permit, and one for the value of the rather valuable tree.

Tape works fine in the nursery because there is no one there to do anything sleazy. Besides, paint would be messy. Many years ago, we used red tape for stock that needed to be disposed of, orange tape for stock that needed to be shifted into the next larger size, and blue tape for stock that was sold and needed to be moved to a holding corral or loaded onto a delivery truck. Of course, different nurseries might use different colors and a different code.

For the sort of tree work that I was involved with, orange or red paint was used only on trees that were to be removed. It would not have been appropriate to tag good trees with paint! We usually marked trees for removal with a circled ‘X’ or just an ‘X’, in a very visible manner.

Surveyors use paint in a more discrete fashion, with single dots or other small markings of paint down near the ground. They use a variety of colors and a standardized code system. The paint is not permanent, and weathers away after a year or so. Some trees get tagged for pruning for clearance from utility cables. Some get tagged for clearance above roadways and sidewalks. A few that are hazardous or in need of such severe pruning that they will be ruined in the process get tagged for removal. Each color of paint means something different. Each specific tag is a message to whomever is responsible for the prescribed procedure. Some who are responsive to the coded messages work for the respective municipality. Others work for a utility company of some sort. They may not know what all the tagging means, but they recognize the meaning of the tags that are addressed to them.

That is why, when a client asks me what a particular tag on a tree means, I can only say that I do not know. I know what tags my associates use, and I can guess what a prominent circled ‘X’ or an ‘X’ means because I know of so many arborists who use that tag. I do happen to know what the bright orange tape around the bay tree above means because my associate put it there. However, I do not know what a blue dot, green dot, yellow dot, orange vertical line or red horizontal line mean.

Arborists Are Physicians For Trees

71108thumbBefore the storms of winter get here, it might be a good time to make arrangements to get some help for big trees that need it. Smaller trees that can be reached from the ground may not need anything that we can not do ourselves. It is the big trees that have grown beyond our reach that may need professional help if they have problems. They are unsafe for us DIY garden enthusiasts.

Once late autumn and winter weather patterns start, storms can break limbs and destabilize trees. Identifying problems and executing necessary remedies can limit such damages before they happens. Disproportionately heavy or structurally deficient limbs can be pruned to reduce weight and wind resistance. Obtrusive limbs can be pruned for clearance from roofs and anything else.

Trees are the most significant and influential features of our gardens. They shade and extend their limbs over our homes and gardens. Not only can they cause serious damage by dropping limbs or falling, but they can also change how our home and garden are affected by their shade. They are worthy of proper maintenance, even when it is necessary to procure the services of an arborist.

An arborist is a horticulturist who specializes in arboriculture, which is the horticulture of trees. Arborists are essentially tree physicians, who evaluate the health, stability and structural integrity of trees, and make recommendations for maintenance, or to repair problems. Most municipalities require an ISA Certified Arborist report in order to issue a permit to remove an unsalvageable tree.

The ISA is the International Society of Arboriculture. Certified Arborists have passed an examination of their arboricultural expertise, and maintain their credentials by continued involvement with ISA educational seminars, classes and workshops. More information about the International Society of Arboriculture and local certified arborists can be found at the website,

Arboriculture is not the sort of thing that gardeners should be expected to perform. It is completely different from the sort of mowing, shearing and pruning that they do. Sadly, much of the damage that arborists find in trees was caused by improper arboricultural procedures. Arboriculture also has the potential to be very dangerous to someone who lacks adequate training and equipment.