Six on Saturday: Locust

 

John the Baptist did not really eat orthopteran insects out in the desert. The locust he ate were the beans of the carob tree, Ceratonia siliqua. They are actually quite nutritious. Supposedly, they are known as locust because they resemble the elongated abdomens of the insects with the same name. A few other related trees that also produce beans are collective known as such.

Robinia pseudoacacia happens to be known as black locust, even though there is nothing black about it, and the tiny and papery beans do not even remotely resemble insects. Supposedly, it arrived with Gold Rush prospectors who wanted something of their homes in Eastern North America. It naturalized aggressively, and is now an invasive exotic species in much of the West.

We tolerate a few at work. They are too pretty to cut down without a good excuse. However, one gave us a good excuse when it fell last winter. It was notably polite about it, by falling into a gap between two roofs that a cat could jump across. Damage was very minimal. Nonetheless, the tree and its destabilizing associates needed to be removed. They are gone but not forgotten.

1. Thorns of black locust only look blurry in this picture. They are wickedly sharp! The sharpest are on the most vigorous stems, which is exactly what the freshly cut stumps here generate.P90921

2. Thickets of suckers (or watersprouts) like these developed where black locust trees were cut down last winter. Most developed on freshly cut stumps. Many emerged from random roots.P90921+

3. More than half of the suckers from the formerly impenetrable thicket around the stump at the center of the picture were removed to relinquish space for the lauristinus in the foreground.P90921++

4. A few bay trees got cut down with the black locust trees. I wanted them coppiced, but was away when they instead got VERY badly pollarded. Oh, the shame! (I will coppice them later.)P90921+++

5. As nasty as black locust is, it has a few attributes. Spring bloom resembles that of white wisteria, and is almost as fragrant. This finely textured pinnately compound foliage is quite elegant.P90921++++

6. Their high and open canopies provide nice shade too. It is just enough for warm summer weather, but not too much to exclude turf grass and understory plants that tolerate partial shade.P90921+++++

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

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Horridculture – Opposite Poles

P90904This is not about North and South. It is about a utility pole and a pole that remained from a redwood tree that was too close to it. One is there to support a variety of cables and a streetlamp. The other just wanted to grow into a redwood tree to join the rest of the forest. One has been deceased for many years or decades. The other was alive just recently, but is now only a stump.

The picture above shows how many cables the utility pole supports, as well as the streetlamp. When I did my internship in 1988, the arborists whom I worked with knew what each of the various cables were for; high voltage, lower voltage, cable television, telephone and whatever else was up there. Fiber optic cables have since simplified the telephone and television cables.

The picture above also shows how the unfortunate redwood tree needed to be cut back for clearance from the electrical cables. I was mortified to see this so prominently visible on the edge of a main road, because I should have noticed the problem earlier and just cut the tree down. Not too long ago I was pruning many other redwood trees for clearance from other streetlamps.

Those who pruned it instead, along with any other trees that were encroaching into the electrical cables, were very efficient with establishing clearance, but not so proficient with aesthetics. Obviously, I could not leave this tree like this on the side of the road. Even if I did not care what it looked like, I did not want it to regenerate and immediately encroach back into the cables.

The picture below shows my corrective pruning. The stump is certainly not dead, and will try to regenerate, but will be easier to keep down. If kept down long enough, it may eventually die.

The second picture below shows the stripped trunk in two sections that are nearly eight feet long, and a short bottom section that is a bit more than two feet long. The two long sections are straight enough for gate posts (although there is another plan for them). It is a sad demise for the formerly healthy and sound redwood tree, but became necessary to keep the electricity on.P90904+P90904++

Props

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.

P90901+

Bad Pollard


P90831KJust about any other arborist will insist that any pollard is a bad pollard. I am not any other arborist. I have no issue with pollarding certain trees properly.

Pollarding is severe pruning that removes all growth that developed since the last pollarding procedure, leaving only a main trunk and a few main limbs. It is done while trees are dormant in winter, and must be repeated either annually or at least every few years, before the resulting growth develops into major limbs. Pruning must be very thorough and neat, leaving no stubs.

Most new growth develops from where older growth had been pruned away during the previous winter, with only a few adventitious stems possibly developing on the main limbs or trunks. Distended ‘knuckles’ develop where this growth repeatedly gets pruned away and regenerates. All subsequent pollard pruning must be done only on the outside of these knuckles, not below.

It may seem easier to cut entire knuckles off with fewer big cuts rather than cutting all the secondary growth off with so many more cuts. However, as new growth develops, the many small cuts on the distended knuckles will be compartmentalized (healed over) much more efficiently than fewer but larger wounds. Wounds that compartmentalize too slowly stay open to decay.

Once pollarded, a tree will always need to be pollarded, or at lease pruned regularly to compensate for compromised structural integrity. Secondary growth is innately vigorous and heavy, but weakly attached to the main limbs.

Pollarding is done to produce an abundance of lush foliage, to produce an abundance of twiggy growth, or to deprive a tree of bloom. Pollarded mulberry trees provide lush foliage to feed silkworms. Pollarded willow trees provide many uniform limber canes for basketry. Pollarded privets are unable to bloom and bother those who are allergic to their objectionably fine pollen.

Well, enough about pollarding.

I pollarded a blue gum, Eucalyptus globulus, for the second time earlier this year. It was done dangerously late in the season, and at the same time that the roots of the tree were brutally damaged by relocation. (It is a canned tree that rooted into the ground.) The tree has no branches, but only a single ridiculously bare trunk with a silly new knuckle on top. Oh, the shame!

As you can see, the unfortunate tree has not grown much since then. It is now getting to be September, so the tree will not be growing much through autumn. As much as I would prefer to pollard this tree annually, I will likely not pollard it this winter, but instead let it grow for another year before pollarding it again. The blue juvenile foliage is exquisitely aromatic, but scarce.

For this picture, I could have moved the tree away from the fence that it is tied to for support, but the barbed wire somehow seems appropriate.

Six on Saturday: The Shining

 

‘Shiners’ have nothing to do with Rudbeckia hirta, which is commonly known as ‘black eyed Susan’. (Why did rude Becky hurt Susan like that anyway?) Shiners are the wounds left from pruning significant limbs from their supporting limbs or main trunks. They shine most blatantly when fresh, and then fade in the weather.

The best shiners are those that will be compartmentalized (healed over) most efficiently. They should not be cut too deeply, or be left with stubs that interfere with compartmentalization. There is quite a bit of science to shiners.

1. This is a good example of a bad shiner. (I could have gotten a better picture of it, but thought that the sun shining from behind was appropriate to the topic.) This shiner was not made by pruning a limb away from a main trunk, but by pruning a main trunk away from a limb. The main trunk leans over so much that most of it needed to be removed to maintain minimal clearance over a driveway. The only two options were to prune it back the the limb on the left, or remove the entire tree. Because the shiner is wider than the remaining limb, which will become the main trunk, it will take several years to be compartmentalized. By that time, decay will have extended downward from the shiner into the main trunk below.P90824

2. Removal of a limb that was battering the topsides of delivery trucks left the shiner above and left of the center of the picture. The scar to the lower left of the shiner, and another scar farther the lower right, closer to the lower right corner of the picture, were caused by a single altercation with one truck that drove off the edge of the driveway. Since it is not really encroaching into the driveway, or interfering with minimal clearance, this particular damaged limb remains.P90824+

3. This is the thrashed limb that was removed from the limb in the #2 picture above. The freshest damage is still red. This limb had been up above minimal clearance for a few years before the supporting limb sagged with the weight of the growing canopy above. Damage to the trucks is more of a concern than the limbs, so it had to go.P90824++

4. This is another good example of a bad shiner. The main trunk to the right would not have been able to compartmentalize over the stub until it grew out past it, or the stub rotted and fell away. The stub was partly rotten, but also partly viable, with a small branch growing from it. The viable portion would have taken more time to rot away. The whole mess was cut away after this picture was taken; but the resulting shiner that I did not get pictures of has another problem. This picture shows how the stub wraps around the main trunk from behind. The bark compressed between the stub and the main trunk, which is known as ‘included bark’ or ‘bark inclusion’, will temporarily be in the way of compartmentalization of the shiner. Fortunately, the tree is young and vigorous enough to figure it all out.P90824+++

5. What looks like shark jaw bones without the teeth is the callus growth that once surrounded a well cut shiner. After the shiner was cut, and the tree started to compartmentalize over it, the tree died suddenly. As the trunk decayed, this dense callus growth that started to compartmentalize the shiner decayed slower. The uniformity of the callus growth shows how evenly the shiner was cut. I believe that the bottom of the shiner is to the left, but that could be backward. I can only say that the shiner is sideways in this picture.P90824++++

6. Coast live oak, Quercus agrifolia, is the only species in all five of the pictures above, and also provided the biscuits to the lower left and the upper right in this picture. ‘Biscuits’ are sometimes cut to adjust a shiner after the main part of a limb is pruned away, or perhaps to cut a stump slighter lower after a tree is cut down. I really do not remember why I saved the biscuit to the lower left, although I can remember the tree that it came from. The fresher one to the upper right is from the shiner in the first picture #1 above. I kept the Hollywood juniper biscuit to the upper left because I thought it would smell like the related Eastern red cedar (which is actually a juniper rather than a cedar) that cedar chests and closets are made with. The deteriorating biscuit to the lower right is from a very dead white fir that needed to be cut down. I kept it because I happen to be very fond of white firs, but so rarely see them here.P90824+++++

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

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Can’t See The Tree For The Forest

P90818Big trees get big problems. Part of our job is to tend to these problems before they become dangerous. Many of these problems are somewhat easy to identify. A deteriorating ponderosa pine with browning foliage it difficult to ignore if it is tall enough to be seen above the rest of the forest more than a mile away.

There are a few problems that are not so easy to identify. Some are caused by the weather, without prior warning. Others are hidden in the forests. One might think that those in the forests would not concern us. However, our landscape and facilities are so intricately mixed with the forests.

The shiner in the picture above was where a big broken limb needed to be cut from a big fir tree. It may not look big in the picture, but the limb was probably more than nine inches wide, and long enough to weigh a few hundred pounds. The lower right edge of the shiner is frayed because the limb broke right at the trunk, and was hanging vertically against the trunk.

The yellow arrow in the picture below indicates where the shiner is located. The trunk of the tree is not as tapered as it seems to be in the picture. It only looks like this because it is so tall that the the upper portion is very far from the camera! Although this fir is a wild forest tree, it is only a few feet from the cabin below. The broken limb was dangling directly over the roof!

There was no way to predict that this limb would break. It did not seem to be any more structurally deficient than those that remain. Of course, once broken, it was removed faster than I could get a picture of it.P90818+

Horridculture – Stumpy

P90814Among pines, firs, redwoods and most excurrent trees (with central leader trunks), stubs or stumps of limbs that were shed are common and more apparent than they are among decurrent trees (which branch into many main limbs). The older lower stubs slowly but eventually decay and fall away as the trunks compartmentalize (heal over) where they were formerly attached.

However, wild trees are rarely completely without such stubs. As the older lower stubs are shed, newer stubs develop higher up. The worst of their stubs get pruned away only when more refined landscapes are developed around such trees, and they get pruned accordingly. If the trees get groomed regularly every few years or so, not many new stubs get a chance to develop.

When pruning out viable limbs, they must be cut cleanly from the trunk or supporting limb, without stubs. Since they do not deteriorate slowly before falling away, the trunk or supporting limb has no time to start the process of compartmentalizing (healing) over where such limbs were attached. Cutting away cleanly eliminates as much obstruction to that process as possible.

Pruning necrotic stubs from trunks of excurrent trees is not quite so important because the trunks have a tendency to start the process of compartmentalization as such stubs are decaying, and can actually constrict and crush stubs if they do not fall away efficiently enough. Nonetheless, necrotic stubs get pruned out when trees are groomed, just because they are unappealing.

So, no matter what, stubs should not be left when pruning. It is not complicated. It is actually easier to control a saw when it is up against a tree trunk or main limb. Yet, many who do not know better, and many who really should, more often than not, leave trees looking like this fir tree.

No Cherry On Top

P90811Weeping flowering cherry is another type of tree that almost never gets appreciated like it should. Like so many Japanese maples, they get planted into situation where so-called ‘gardeners’ shear them into nondescript globs of worthless foliage that only get in the way. Some get shorn so regularly that they are deprived of bloom. Their form and bloom are their two main assets.

The climate here is not easy on them either. Although comfortably mild, the climate is also arid. This aridity enhances the potential for sun scald of exposed bark. Because upper limbs bend over to hang back downward, their bark is more exposed than that of upright flowering cherries. Consequently, upper limbs are often scalded and ruined, disfiguring the remaining canopy.

Pruning can be complicated. Removal of scalded upper growth exposes inner growth that is more sensitive to scald. It is sometimes necessary to leave damaged upper growth until it gets replaced from below by newer growth. Regular pruning to remove as much of the superfluous lower growth as possible should stimulate more vigorous growth among the stems that remain.

This is really the best technique for preventing scald among upper growth. It may sound silly, but pruning from below to concentrate growth into fewer stems that extend from or through the top of the canopy keeps the top of the canopy healthy and resilient to scald. It also elevates the pendulous canopy that needs to be pruned very regularly for vertical clearance anyway.

It is not easy to see in this picture, but this small weeping cherry tree is developing two distinct canopies. The original upper canopy was damaged by scald and is now disfigured. It is mostly to the upper left of center of the picture. A more symmetrical inner canopy that is developing where superfluous inner growth was pruned out last winter is evident below and to the right.

If there were not a walkway so close to the tree, and I were not concerned with maintaining vertical clearance, I could prune the upper canopy back over a few years, and subordinate it to the healthier lower canopy as it grows through it. Instead, I will prune out most of the inner canopy, leaving only a few vigorous stems that can replace what is missing in the upper canopy.

There is no need to be concerned with it now. The lower stems are not too obtrusive yet. They can bloom next spring, and get pruned out next summer before they really do get obtrusive.

Six on Saturday: Do Not Sit On Tree

 

1. Seriously!P90810

2. Allow me to explain. This is one of three small but very gnarly coast live oaks that grew from the roots of a single tree that was cut down or fell several decades ago. Because the trunks of the three trees are so horizontal and sculptural, children climb on them. Sometimes many children sit on the trunk of this particular tree to get their group picture taken. We had been concerned about how this might compromise the stability of the tree for quite a while. Before we constructed suspension devices to prop it and one of the other two trees with, it destabilized and sagged! We pruned much of the canopy away to eliminate some of the weight that exerts so much leverage against the root system, and propped the trunk with a saw horse. We hope that the tree survives the loss of roots that likely broke away in the process, but would not be surprised if it does not. We are not ready to cut it down. It and the two other trees are so well known and popular among guests. The sign is visible to the right. I will explain the colored yarn on the trunk in a moment.P90810+

3. The subject tree is to the lower right in this picture. The two other trees are sprawled to the upper left. The tree that extends farthest to the left will get propped as well. All three have been pruned more aggressively than they should have been to eliminate much of the weight.P90810++

4. The yarn on the trunks is decoration that the camp counselors installed prior to the arrival of the guests. It must have taken a long time to wrap this much yarn around the trunks, and there is a whole lot more in many other trees. I wrote about it earlier in ‘Boom! Zap! Wow! Bam! Zing!‘.P90810+++

5. This is a completely different coast live oak, with a completely different problem. It needed to be pruned for clearance from an adjacent roadway and walkway. The major limb that was here supported less than one tenth of the total canopy, but because it had been cut back repeatedly, it was unusually bulky. Consequently, the shiner that remains is about as wide ad the remaining trunk! That is VERY arboriculturally incorrect. To make matters worse, the cut was not at the correct angle, so eliminated the lower half of the ‘collar’ that is supposed to expand to compartmentalize (heal) the shiner. The problem now is that by the time the shiner heals, the interior of the trunk may be so rotten that the tree may need to be removed anyway. The limb needed to be removed. The only other option was to remove the entire tree.P90810++++

6. Nothing was done to this coast live oak. It grew like this naturally. Although not an exemplary specimen, it certainly is impressive.P90810+++++

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

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/

Suckers For Street Trees

P90804This grand sycamore has likely been here since the third day of Genesis. A few of the top branches got broken off when Noah’s Ark floated over. When I was a little kid, it was on the edge of a vacant field where road debris was dumped, and older kids rode their dirt bikes. Now it is on the western edge of the parking lot of Felton Covered Bridge Park. I write about it sometimes.

California Sycamore‘, ‘Hanging Gardens Of Babylon‘, ‘Nature Is Messy‘ and ‘Tufts‘ are some of the articles that feature this exquisite specimen. The last three of these examples describe some of the difficulties of old age for sycamores. Something that I may not have mentioned in these article though, is that such mature sycamores eventually develop root suckers.

I use the term ‘suckers’ loosely. For those of us who grow grafted trees, ‘suckers’ are stems that develop from below the graft unions of grafted trees, even if above the roots. They are from the understock below, so are genetically different from the scions above. Unusually vigorous stems above graft unions or on ungrafted trees, including the roots, are known as ‘watersprouts’.

For all other intents and purposes, ‘suckers’ really are just vigorous stems that emerge from roots, which is what we have here. Because no one was here to graft this grand sycamore on the third day of Genesis, these ‘suckers’ are genetically identical to the main tree. Unfortunately, their appearance indicates that the tree is finally acknowledging that it is slowly deteriorating.

Many trees do it, especially old riparian trees. When they know that they will not be around much longer, but still have some time to do so, they divert resources into their own replacement. Suckers are expected to mature into new trees after the original is gone. They recycle the mature original root system until they eventually replace it with younger and more vigorous roots.

Arborists may try to interfere with this process by removing suckers and watersprouts, and diverting resources back into older stems. This is actually helpful for trees that are distressed, but not yet decaying. For trees as mature as this sycamore, removal of vigorous suckers and watersprouts is mostly cosmetic, because thickets of such rampant growth becomes unsightly.

As violent as it sounds, it is best to abscise suckers like these when they first appear, and any that appear afterward. That involves literally tearing them from their roots to remove some of the callus growth from which they emerged. Cutting them at the ground not only leaves the callus growth to develop into distended burls, but also stimulates more vigorous sucker growth!

Now that these suckers have been cut down repeatedly over the past several years, simple abscision is no longer possible. Callus grown has expanded and fused into broad subterranean burl growth. Removal of such extensive burl would severely distress and possibly contribute to the destabilization of the already distressed tree. Suckers can now only be cut down to the ground.

Several years ago, when the first of the suckers started to appear, they were much easier to abscise. The process was delayed until winter dormancy. The small defoliated suckers were then abscised along with much of their associated callus. It did not accomplish much for the massive tree, and only delayed the inevitable for a few years, but generated an interesting byproduct.

The bare suckers with their bit of callus were ideal for growing into copies of the same tree. Most were plugged back into the riparian area nearby, but later killed by necessary vegetation management. A few others were canned (potted), and grew into small sycamore trees that were planted, with other sycamores, into broad medians and parkstrips in Mid City Los Angeles.

It is a long story about how those few trees ended up in Los Angeles, and were added to the fifty or so Birthday Trees that we plant annually on January 18. Sadly, their identities were lost in the process. If the other sycamores are genetically identical clones of each other, it may eventually be possible to distinguish genetic variations of those that were once root suckers here.