This article from three years ago definitely conforms to the ‘Horridculture’ meme for Wednesday.

Tony Tomeo


I use the term loosely. Okay, so maybe I use it mockingly in this context. This sort of thing really should have no connection to the works of Calder, Rodin or Brancusi. It might be worthy of a few fancy adjectives, such as ‘severe’, ‘unusual’, ‘dramatic’ and ‘bold’. Horticulturally though, we might be thinking more like ‘disgraceful’, ‘abhorrent’, ‘ridiculous’ or ‘just plain sad’.

There is nothing wrong with pollarding, that severe sort of pruning that almost all other arborists will tell you is wrong. It involves pruning trees back to the same distended terminal knuckles every winter. Only a few trees are adaptable to the technique, and technically, sweetgum happens to be one of those few trees.

The stipulation is that once pollarded, they MUST be cut back to the same knuckles EVERY winter. A small stub or maybe two can be left on knuckles to allow them to elongate…

View original post 470 more words

Tree Surgeons Evolved Into Arborists

Tree surgeons maintain the big trees.

Arborists are very specialized horticulturists. They prefer to work with trees. Of course that is not as simple as it sounds. Some are nurserymen who grow trees. Some select appropriate trees for landscape design. Even some of the orchardists who work with many trees of a similar type have earned this prestigious designation. Decades ago, we still knew many of them as tree surgeons.

Arboriculture, which is the specialized horticulture of trees, has certainly evolved through the decades. Tree surgeons no longer graft fruit trees directly in home gardens. Nurserymen graft trees in production nurseries, to make them available from retail nurseries. However, modern tree surgeons now work with much more diversity of many species that were unknown to their predecessors.

As storms become more frequent through autumn and winter, the need for arboriculture becomes more apparent. More unstable trees fall. More structural deficient limbs break. Many trees prefer to be pruned while dormant through winter. In actuality though, arboriculture is important throughout the year. Some procedures, for some sorts of trees, should happen significantly earlier or later.

Trees are the most substantial features of home gardens. Once they grow beyond reach, they need to be maintained by qualified tree surgeons. Regardless of what most say, very few gardeners are qualified to perform major arboricultural procedures. Many tree surgeons will attest to finding that most damage that trees endure is caused by gardeners with minimal regard for arboriculture.

Tree surgeons who are Certified Arborists of the International Society of Arboriculture, or ‘ISA’, have demonstrated their proficiency with arboriculture. After passing their certification examination, Certified Arborists maintain their credentials by continued involvement with educational seminars, classes and workshops of the ISA. Not many other horticultural professionals are so dedicated.

More information about procuring the services of an ISA certified arborist can be found at

Mature Trees Need Professional Help

Arboriculture is specialized horticulture of trees.

Arborists are horticulturists who are specialized with the horticulture of trees, which is known as arboriculture. In urban gardening, they are not as familiar as gardeners who mow lawns and tend to the annuals, perennials and shrubbery that are close to the ground; but they should be. The trees that arborists maintain are the most significant features in most landscapes.

Bad annuals or poorly tended lawns can get unsightly, but are not too hazardous. However, a tree can be extremely hazardous if it becomes unstable or develops structural deficiency. Falling trees or limbs are very dangerous, and can cause all sorts of damage to anything within reach. Arboriculture is therefore the most important horticulture in home gardens with trees.

Sadly, many trees are severely damaged by improper pruning, which is often performed by those hired to prune them. Some get pruned too severely, or get pruned in the wrong season. Others do not get pruned aggressively enough. Either way, many get structurally compromised so that they drop limbs as they mature. Some trees get damaged too severely to salvage.

This is precisely why arboriculture should be done by qualified arborists. Unfortunately, finding such an arborist may not be as easy as it would seem to be. The industry is notoriously overrun with ‘hackers’, who are unfamiliar (and often unconcerned) with what trees need, and how trees respond to improper pruning.

The International Society of Arboriculture, or ISA, certifies arborists who pass an exam of arboricultural expertise. ISA certified arborists maintain their certification with regular involvement with the ISA, which involves arboricutural seminars and classes, as well as networking with other professional arborists. Certified arborists can be found at the website of the ISA at

Arborists Maintain The Big Trees

91106thumbThe trees know what time of year it is. Even evergreen trees have shed some of their older foliage through late summer. Deciduous trees generally start later, but will be more blatant about their process as they defoliate completely through autumn to winter. Some get strikingly colorful first, as if to brag about it. Foliage is not so important during shorter days and dimmed sunlight anyway.

By the time storms start to arrive later in autumn, trees intend to be ready. There will be less foliage to be blown by wind, or to absorb the weight of the rain. Remaining deciduous foliage is likely to be dislodged by wind and rain before supporting limbs succumb. Trees will be mostly dormant, so will not mind so much if a few minor limbs do happen to get broken. They know their routine.

For many types of trees, this is a the best season for major pruning. While dormant, they are much less likely to be offended by it. In fact, they sort of expect to wake up in spring with a few limbs missing. They do not distinguish what was pruned away from what might have been broken by the weather. Besides, it is better to prune questionable limbs civilly, before they get broken brutally.

Trees that are beyond reach will need the attention of professional arborists.

Arboriculture is merely the horticulture of trees. An arborist is therefore a horticulturist who specializes in trees. They assess the health, stability and structural integrity of trees, and prescribe any necessary arboricultural procedures. They or their associated crews are qualified to perform the work that the trees need. The most proficient of arborists are those who are certified with the ISA.

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


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.

Bad Root Pruning

P81118-Root pruning is nothing new. It is done more commonly than we think about for many aggressive perennials like lily-of-the-Nile, that like to disperse their roots into areas where we want to grow more docile annual bedding plants or vegetables. We might do it halfway, or more, around a shrubby plant during spring or summer if we plant on digging and moving it the following autumn. For most small and low profile plants, root pruning is sort of tolerable. The plants that we do it to may not like it, but it is sometimes necessary, and better than not doing so.
Trees are not like most small and low profile plants. Most are very sensitive to root pruning when mature. They are not so proficient at replacing the portions of their root systems that they are deprived of. Large roots that get severed are very susceptible to decay, which slowly migrates inward to the rest of the root system. Obviously, depriving trees of roots compromises stability to some extent. Because roots are below grade, it is impossible to know the extent of the damage caused by root pruning while it is being performed. This is a classic example.
The exposed freshly cut surface to the left in the picture above is not the stump of a small tree that was just cut down. Although it is, in this picture, a horizontally oriented cut surface of what seems to have been something that was standing vertically, it was actually cut vertically through a horizontally oriented root. Yes, that is it in the yellow oval to the right. It was cut because it was displacing the adjacent asphalt pavement, as demonstrated by the picture below. Rather that trouble us with this concern, the resident of the adjacent home cut the root of this mature photinia tree to protect his driveway from more damage.P81118+

The problem was that the major root that was severed was all that was supporting the tree. (The cut surface of the severed root is in the middle of the picture below.) The roots to the left and right of it may seem to be substantial in the picture below, but were mostly decayed stubs left from earlier root pruning. I was able to wrestle the stump out to dispose of it, without cutting more roots. The lack of other substantial roots is probably why the primary root was so big and expanding actively enough to displace the pavement.P81118++

The funny thing about all this is that I would have done the same thing. I would have determined that, although the tree would be very distressed by the loss of such a major root, it should not have been too terribly destabilized, and should have been likely to eventually recover. Even if it eventually succumbed to the distress, the loss of this mature but small tree would have been a better option relative to continued damage to the paved driveway. I certainly would not have expected it to simply fall over as it so comically did. The picture below shows what had been vertical trunks of the photinia tree that were quite horizontal after it fell over. The fractured asphalt pavement is visible at the far right edge. The top of the tree reached the center line in the adjacent roadway. I am sorry that I did not get a more amusing picture of it blocking the lane. I was in too much of a rush to clear the roadway at the time. This was something that I really was not expecting to encounter at work.P81118+++

More Spontaneous Limb Failure

P80707KP80707K+(This was copied and modified from the Facebook page of Felton League.)

Warm and humid weather is an uncomfortable change for an otherwise mild summer. It also causes spontaneous limb failure among trees, particular those in riparian areas or irrigated landscapes. What sounded like muffled firecrackers was the (slow but steady) fracturing of another cottonwood limb in Felton Covered Bridge Park. (Another incident of spontaneous limb failure was mentioned a few days ago.) ( This one was over the picnic area adjacent to the playground. The fallen portion of the limb was less than a foot in diameter, although it was slighter wider than a foot wide where the fracture originated. It fell onto the middle of a group of picnic tables, with the fractured proximal end remaining suspended and attached to the originating tree. Because it remained attached and fractured slowly, the limb did not fall with enough inertia to damage the picnic tables. It was removed very efficiently.P80707K++(continued)

Cottonwood, sweetgum, coast live oak, valley oak, Chinese elm, California bay, California sycamore, willow and various eucalypti are particularly susceptible to spontaneous limb failure. The oaks and eucalypti are particularly dangerous. Oak limbs are extremely heavy, and tend to break away cleanly and suddenly rather than fall slowly while still attached. Eucalypti limbs likewise break away cleanly, and then fall from great heights without many lower limbs to slow them down. As they start to fracture, Chinese elm and willow limbs might stay attached to the main trunks or the larger limbs from which they originate, which might slow them down somewhat.

Sadly, spontaneous limb failure does more than damage whatever the falling limbs land on. It can also disfigure the affected trees so severely that they must be removed rather than salvaged.P80707K+++

Not So Fruitless Cherry Trees

P80520The ‘politically correct’ designation for them now is ‘flowering cherry’. We all know what it means, but it is not quite as accurate. After all, they all flower. Fruiting cherries can not make fruit without flowering first. The old fashioned designation as ‘fruitless cherry’ is more accurate, but not so appealing. Besides, after half a century, the work of these two deteriorating old fruitless cherry trees has not been in vain.

We are not certain what cultivar they are. I think of them as ‘Akebono’ because that is what I am familiar with. However, those who have been acquainted with them longer know them as ‘Yoshino’. The tree structure seems to be more similar to that of ‘Akebono’. The bloom seems to be more similar to that of ‘Yoshino’. My Mother happens to like ‘Akebono’, so if she ever asks, I know what to say. However, I would tell my Pa that they are ‘Yoshino’ because that happens to be the middle name of his newest son in law, who he gave my baby sister #5 away to. It does not really matter what their name is. They are some of the most important trees in the neighborhood.

You would think that with all the very old and very big redwoods here, that these puny and decrepit flowering cherry trees would not be all that important. Some of the redwoods are hundreds of feet tall and hundreds of years old. They will still be here for a very long time after the flowering cherries are gone. Flowering cherries can last for centuries where they are happiest and pampered in old gardens in Japan, but rarely last half a century here, even in the best of conditions.

However, everyone in the neighborhood knows these cherry trees. There are only a few people who can remember before the trees were planted in the late 1960s. They are spectacular in bloom, particularly with the dark green backdrop of the rest of the landscape and redwoods. The picture below shows a close up of the bloom about a month and a half ago. One can imagine the entire canopy of the trees covered with this bloom before new foliage appears. It was even more spectacular years ago, before the canopies started to deteriorate and die back. There is not much left of them now.

They really are as bad as they look in the picture above. The closer of the two trees is just a stump with that silly little stub on top to make it look even more disfigured. I could not cut off the stump because some of the minimal remaining viable stems originate there. It does not matter much. There is no way to repair these trees, or make them any prettier. Either of the trees could die at any moment. We are ready to plant at least one replacement, although we will likely only plant one. The objective is to restore the bloom that was there before, but we know that there is no replacement for the trees that those who are familiar with are so fond of.

I have worked with MANY trees through my career, including a few that are (or were) very cultural significant. I was very disgusted by the lack of respect for a group of historic redwoods that used to be outside the old City Hall in Sunnyvale before the mall was build around them, over the area that used to be downtown. I inspected the big old coast live oak at the Scott Residence in Scott’s Valley, where the founder of the town resided. Again, I was saddened by the lack of concern from people who live there now but know nothing of local history, and care even less. At the Winchester House, I witnessed idiotic mislabeling of the historic California fan palms flanking the driveway, as well as blatant lies about their history. Well, I could write another article about this rant. These not so fruitless flowering cherries do not fit into this category anyway.

It seems that everyone is aware that the flowering cherries will be gone soon, and they understand why. No one questions the need for removal. It is saddening anyway. Yet, it is also gratifying to know that these trees are appreciated and respected as much as they are. Those who know them appreciate all the work they put into making their lives a bit more colorful and happier. For half a century, these flowering cherries have been doing what they were planted to do. They had a very good and fruitful career.P80414

Big Trees Really Need Arborists

41203thumbStormy winter weather always reminds some of us that our trees need some attention. Wind can break limbs. If the weather gets really nasty, trees can be destabilized by strong wind, particularly if the soil is moistened by rain. However, the truth is that arboriculture, which is the horticulture of trees, is important throughout the year. We just become more aware of it when weather threatens.

Not only is arboriculture important throughout the year, but it is also the most important aspect of horticulture in most gardens that are outfitted with trees. After all, trees are the most significant features of such landscapes. Their shade affects the homes and garden spaces around them. If they drop limbs or fall, they can cause significant damage. Many get far too big for us to maintain.

This is why we need arborists, the horticulturists who specialize in trees. Arborists can evaluate the health, stability and structural integrity of trees, and prescribe any necessary arboricultural procedures. In order to issue a permit to remove a tree, most municipalities require an inspection and report from an arborist who is certified by the International Society of Arboriculture, or ISA.

ISA Certified Arborists have passed an examination of their arboricultural expertise, and maintain their certification by continued involvement with ISA educational seminars, workshops and classes. The ISA is the standardizing resource for the promotion of the most important arboricultural technology, and maintains discriminating standards. ISA certification is quite a commitment., the website of the ISA, is an excellent resource for anyone in need of the services of a certified arborist. The registry of arborists can identify and find an arborist directly by name, or regionally by city or ZIP code. The site is also useful for information about proper arboriculture and trees, for those of us who maintain our own small trees, or want to select new trees.

Trusting the wrong professional to maintain trees can be very risky. Even gardeners who are proficient at mowing lawns and shearing hedges may not be adequately knowledgeable about proper arboriculture. Instead of correcting problems, improper pruning can disfigure trees and limbs, and actually compromise their structural integrity. Sadly, it is not uncommon for otherwise healthy, stable and well structured trees to be ruined by those hired to care for them.