Dr. Shigo and tree pruning

[Martin Sweeney]

Attila,

Perhaps rather than asking Bonsaiists to wrap their ends around Dr. Shigo's means, maybe we should ask what is Dr. Shigo trying to acheive with his means and methods? Isn't he a landscape arborculturist(which is a good thing to be)? Isn't he trying to promote healthy, natural trees growing to full size and maturity (dignity?) in spite of living in an environment dominated by the needs of man? To reach full size and maturity (dignity?) he understands (and is almost certainly correct) certain methods of human interaction with trees lead to best results for the tree and people.

I respect and keep as healthy as possible the trees I grow, but they are dependant on me for their very existance, once I place them in the pot. I understand (and think I am correct, although not as correct as I hope to be one day) that certain methods, different from Dr. Shigo's methods, of my interaction with my bonsai will lead to best results for whatever my horticultural and artistic goals are for my trees as Bonsai.

Regards,
Martin

 

[William N. Valavanis]

When Dr. Shigo "suddenly appeared" and began preaching "his" theory for pruning we invited him to a bonsai convention. I believe it was in Cleveland, OH, over 25 years ago. After his presentation we gave him a Masakuni concave pruner and asked him to play with it.

He returned a year or two later and thanked us for the tool. He said he now had the perfect tool to demonstrate how NOT to prune trees.

I personally feel that the late Dr. Shigo did his research on landscape trees in the field, not on container gown plants which are pruned aesthetically, not necessarily to produce lumber.

But, I do know, after first hand experience of pruning bonsai for over 45 years that if I do NOT seal a pruning wound the new callus tissue will not cover the wound as quickly as if it were sealed. Also if a branch is allowed to remain as a "collar" for quick healing, it will form an ugly scar which is not desired for my bonsai design.

The use of tree would sealants often causes a heated discussion in horticultural circles. But for me, I'll continue to seal my pruning cuts and make them as flush as possible, usually concave for most species

Just my thoughts on this topic.

Bill

 

[Rick Moquin]

This thread has more complexities than (Carter has liver pills), and although Attila seems torn, I personally believe his choice of "word" was wrong in the thoughts he is trying to convey.

It seems to me a while ago there was an incredible fora dissertation wrt the use of wound sealant or not, and the centre of attention, Dr Shigo being a proponent against the use of any type of sealant.

Undoubtedly the man has credentials, but not dissimilar to many individuals his pinions may very well be biased in one way or another. Let me explain...

Outside of bonsai practices Dr Shigo's recommendations against flush cutting and dead heading are sound, in horticultural circles. But we are not doing horticulture perse we are engaged in bonsai.

I am a proponent of wound sealant, both in normal landscaping practice and bonsai. Especially with bonsai as I have seen the results of a properly treated wound in comparison with an unattended one. It's night and day. On the other hand many learnt individuals do not use anything, nursery owners etc... The latter may have indeed added fuel to a well established fire. The long and the short is they don't have time and bottom line they don't really care as long as the product coming in the front door exits at the back.

The trouble starts when we want to cut corners and want to create a large tree in a short time: large trunks, large chops, huge wounds, and carving in big volumes.

May be patience is the answer to create beauty and also respect the tree. May be we start crossing the line when we want it faster and cheaper and lose sight of what the tree needs.
Faster, cheaper, bigger...

... and that my friend is today's society in a nutshell. Instant gratification and I wanted it yesterday.

But even more importantly... I don't want many of the wounds I create to be healed over. That after all was half the reason I created the wound... I wanted the trunk hollowed out for a reason or I wanted that shari on the the top of that root. many times its part of the design of the tree and as long as the tree is not put in any danger of dying then the tree is perfectly fine.

It is also important to remember that the heartwood on a tree is not alive... its only there for structural support which does not usually effect most bonsai. So if bugs eat away at it and it rotts away... good... it adds the vision of age... and survival... the tree doesn't know any different.

... the fine line between an artist and bonsaist. Although both are creators (well one more than the other) the artist feels the need to go to extremes with his creative talent.

worry about you... and not some other person's idea which i don't believe ever took into account the concepts and philosophies of bonsai culture in the first place.

... and this is a very good observation. His work has been discussed at length from a horticultural perspective only. So although undeniably a subject matter expert, how much credence do we extend towards his findings when dealing with bonsai.

I believe we need a strong horticultural foundation in order to persue our passion, but we also need to add the nuances favourable to said passion.

Attila,

Perhaps rather than asking Bonsaiists to wrap their ends around Dr. Shigo's means, maybe we should ask what is Dr. Shigo trying to acheive with his means and methods? Isn't he a landscape arborculturist(which is a good thing to be)? Isn't he trying to promote healthy, natural trees growing to full size and maturity (dignity?) in spite of living in an environment dominated by the needs of man? To reach full size and maturity (dignity?) he understands (and is almost certainly correct) certain methods of human interaction with trees lead to best results for the tree and people.

I respect and keep as healthy as possible the trees I grow, but they are dependant on me for their very existance, once I place them in the pot. I understand (and think I am correct, although not as correct as I hope to be one day) that certain methods, different from Dr. Shigo's methods, of my interaction with my bonsai will lead to best results for whatever my horticultural and artistic goals are for my trees as Bonsai.

Regards,
Martin

Martin,

I fully support your argument but it's essence is once again limited to our passion. Let me extend your thoughts into the landscape for a second.

Many folks just acquire trees from a nursery, plant them in their lawns, feed them (some) and forget about them. Why not ? Mother nature intended it that way no? Well we need to look after their maintenance needs as these trees are growing in a landscape and not in the forest where we don't care that a branch that should have been pruned 10 years before suddenly falls on ones car, damaging the car and leaving an ugly hole where it once was. The tree is now imbalanced and will compensate but never really recover. In the forest we couldn't care less.

Folks have shrubs and allow them to bloom without collecting the flowers (necessary pruning) just to find after years an ugly mess. Trees for cut flowers are meant to be collected. This seasonal maintenance ensures the future blooming needs of the tree/shrub as it only blooms on new wood. The trees balance needs to be maintained. Has bonsaist we understand this but the average homeowner doesn't, just like an overgrown hedge, dead in the middle and they don't dare dead head it. It will be ugly for years (3-5) it took me 20years to grow it to where it is now. No you have been growing roots for 20 years and clipping all the new growth at the cost of balance. A hedge really respond exponentially to periodic draconian measures, in short fashion with astonishing results.

Dr Shigo's thoughts have a place in our culture, but we as enthusiast must decipher the useful beneficial information applicable to us, and have the forethought to dismiss the diatribe.

 

[Ang3lfir3]

just for the record.. I don't use wound selant... never have and never will... but that is a result of my teacher's teachings. I am more inclined to leave a dead branch or jin instead of a simple bullseye. If I must leave a wound on the tree from large branch removal it will be dealt with artistically and in keeping with the vision of age I am attempting to create. Again this is only my approach but one i find satisfying and useful. Regardless of the approach , sealant or no, I believe ultimately that the tree will survive and nature will run its course. Of course sometimes I like to speed that up and that is when the power tools come into play

Tho i don't think Attila is so much concerned at this point with that part of Shigo's thoughts. Instead I believe him to be more concerned with certain techniques mainly used in field growing material for the purposes of creating in miniature what mother nature has created with time and struggle over centuries in full scale.

 

[Anonymous User]

The two main areas of controversy are "Flush cuts" and "Toppings". In bonsai we extensivey use both. We cut the branches with concave cutter (or spherical cutter) for aesthetic reasons: to prevent the formation of buldges and stubs. In Shigo's view flush cuts are the worst, since it prevents the tree from properly compartmentalize the damaged and infected area. Flush cut destroys the tree's defense system and the tree will struggle all its life to overcome this.

The correct way to cut a branch is to remove it at the end of the "branch collar" (this is a small swelling at the base of the branch). The problem is that if we do this on a bonsai, the tree will end up with a swelling at the site of the removed branch.

Actually, there is a school of thought in bonsai which says one should leave a stub at first, and after that has dried out (compartmentalized) then flush cut, this is often recommended for pines at times.

Same with trunk chops. According to Shigo, trunk chop causes the inevitable rotting of the inner wood. And he has pictures to prove it. Topping also destroys the dignity of the tree (he often mentions this notion of "tree dignity").

You are confusing two entirely different techniques. Topping is just that, topping a tree, it is not trunk chopping. In the past, arborists used to "top" a tree to lower it's height, usually done in yards and parks, but this practice actually weakened the tree and resulted in unnatural appearances. The good doctor found that crotch pruning worked better, amazing, this is a technique we often use in bonsai, that is cutting the trunk or branch at a point where another branch can take over as the apex.

Dr. Shigo's findings are often in conflict with arborists. In many cases, arborist perform these practices knowing that they are harmful, but also aware that their business needs these techiques in order to survive.

Only poor arborists, the good ones have no conflict at all, take for example sealant, most arborists these days don't waste their time with it, thanks to the Doctor. As for bonsai, for every bonsaist that uses sealant, there is one who does not, based on this fact alone, it doesn't matter if you do or don't, good results have been achieved either way.

[/QUOTE]

 

[Greg Brenden]

When Dr. Shigo "suddenly appeared" and began preaching "his" theory for pruning we invited him to a bonsai convention. I believe it was in Cleveland, OH, over 25 years ago. After his presentation we gave him a Masakuni concave pruner and asked him to play with it.

He returned a year or two later and thanked us for the tool. He said he now had the perfect tool to demonstrate how NOT to prune trees.

I personally feel that the late Dr. Shigo did his research on landscape trees in the field, not on container gown plants which are pruned aesthetically, not necessarily to produce lumber.

But, I do know, after first hand experience of pruning bonsai for over 45 years that if I do NOT seal a pruning wound the new callus tissue will not cover the wound as quickly as if it were sealed. Also if a branch is allowed to remain as a "collar" for quick healing, it will form an ugly scar which is not desired for my bonsai design.

The use of tree would sealants often causes a heated discussion in horticultural circles. But for me, I'll continue to seal my pruning cuts and make them as flush as possible, usually concave for most species

Just my thoughts on this topic.

Bill

Spot on, Bill!

 

[Klytus]

In my minds eye i can see a Shigo tree,i can see them about town too.

The chinese better get a move on with their Dr Shigo mudmen.

If you want to be a tree surgeon then your first lesson is if it sticks out then chop it off.

Second lesson is to do as little work as possible.

 

[Attila Soos]

Thanks guys for the imput, I think my concerns were answered. After reading Dr. Shigo's book, I felt that it was important to address some of the points in the book that seem to be in contradiction with current bonsai practices. I thing that this would be normal for anybody who is interested in the science of horticulture, and practices bonsai at the same time.
At the end, there should not be any contradiction. The science of large trees may require an approach that is different then in case of miniature ones. We know that, but many of those unfamiliar with bonsai may not. It is important that we answer their concerns.

Bill,
I too believe that some of the findings of Mr. Shigo are relevant to full-sized trees, but not necessarily to trees in container culture. As you said, the quality of lumber is important in the case of large trees, and this would dictate a specific treatment that is not necessary when dealing with bonsai. Also, in the case of large trees, the compromise of heartwood would lead to hazardous conditions, such as danger of collapse - this is irrelevant in the case of bonsai. I purposefully avoided the issue of wound sealant, since there were extensive on-line discussions on this in the past.

Ang3lfir3,
You are right, we can use the knowledge gained by Mr. Shigo during his research, but he would be well advised not to reject the experience gained from our age-old practice of bonsai. May be I was overly concerned to accomodate his ideas into my views on bonsai.

Martin,
Good points, thanks for contributing to this.

Will,
I often practice leaving a stub myself, and later removing it. It is a good practice since it reduces sap loss (especially in conifers), and is less drastic for the tree. I've done this for years, so I was thinking the same as you. But Dr. Shigo specifically mentions that after the tree compartmentalized the wound, flush-cutting will compromise this defense. He also mentions that leaving a stub is just as bad as flush-cutting: both lead to pathogens reaching the inner parts of the trunk and destroying the tree's defense system.
As for topping, you are right, it is not the same as trunk chopping. But in his view, causing large wounds, such as chopping a trunk, will critically compromise the defense of a tree, since the whole section of the heartwood, as well as sapwood, will be exposed to pathogens. Instead, he recommends that one uses corrective measures in the early life of a tree, that require much smaller wounds. This way, the tree can be prepared to defend itself. Chopping down the whole trunk is the most traumatic technique, short of killing the tree. I attached a picture in my early post, showing what happens to the heartwood when the trunk is chopped. There is also a big difference between trunk-chopping a young and thin tree, vs. doing in on an old and large trunk. The young tree has most of it's wood live/active, with little or no heartwood (dead wood, that is). So a young tree has a much easier time to re-generate from trunk chop, than an older one.
All great points.

Rick,
Yes, I touched a great many complexities, any of them could be a matter of debate. I only touched on the philosophical aspects - such as Dr. Shigo's notions on the dignity of trees, respecting them, and how do we define a happy and healthy tree, vs. a sick and tortured tree - since I tried to avoid the thread degenerating into debate on tree suffering and other esoterics. But he is also serious about these issues, and I suspect that he does not share our views on bonsai with enthusiasm similar to ours.
I also agree with you that his views cannot be taken literally, when dealing with bonsai. We may have to take out the useful, and regard the rest with critical thought.

Greg,
Good to hear from you. I hope all is well in the Great North.

Klytus,
I thing the second lesson is the most useful one. It does the least harm, and it saves plenty of time.
I'd love to have a Dr.Shigo mudman.

 

[Rick Moquin]

just for the record.. I don't use wound selant... never have and never will... but that is a result of my teacher's teachings. I am more inclined to leave a dead branch or jin instead of a simple bullseye. If I must leave a wound on the tree from large branch removal it will be dealt with artistically and in keeping with the vision of age I am attempting to create. Again this is only my approach but one i find satisfying and useful. Regardless of the approach , sealant or no, I believe ultimately that the tree will survive and nature will run its course. Of course sometimes I like to speed that up and that is when the power tools come into play

Tho i don't think Attila is so much concerned at this point with that part of Shigo's thoughts. Instead I believe him to be more concerned with certain techniques mainly used in field growing material for the purposes of creating in miniature what mother nature has created with time and struggle over centuries in full scale.

Perhaps you missed my point. A lot of credit can and needs to be extended to Dr Shigo and his work, as with many others. I used but a portion of his teachings to demonstrate how far apart both cultures are. That being said...

Not just on this particular subject but with the advent of the information hwy, we have come to find out that a lot of information is dated. Although this information was once useful and credible, some was/is not applicable to what we are doing. Understanding what transpires and the delta between the two is the key. In other words deciphering the wheat from the chaff and maximizing the best of both worlds towards a common ground.

from Attila...

At the end, there should not be any contradiction. The science of large trees may require an approach that is different then in case of miniature ones. We know that, but many of those unfamiliar with bonsai may not. It is important that we answer their concerns.

exactly; and

Instead, he recommends that one uses corrective measures in the early life of a tree, that require much smaller wounds.

the bold text is where I was going.

 

[rockm]

A lot of hand wringing over something that is not really pertinent. Yeah, large cuts on big trees can kill them. So can large cuts on small trees. You do it as carefully as you can. Hope for the best.

If you start overthinking, worrying about stuff that doesn't really happen (when's the last time you lost a tree to a trunk chop? I have NEVER lost a tree from any drastic pruning. All the trees that I've lost have been the result of some kind of root or soil issue.

As for Shigo, who really gives a damn. I get rather tired of him and his acolytes...He's not doing bonsai, and it appears that he doesn't approve anyway. Bonsai can add dignity to otherwise boring, or even ridiculous trees.

Trees have no diginity, other than that which we impose on them. Trees can't choose how they're wounded in the wild. They adapt and survive Nature's rather imprecise and mostly undignified treatment. They've been doing that for a VERY VERY VERY long time, despite Mr. Shigo's best intentions.

And for what it's worth, bonsai is just a big set of contradictions. It's enormously counterintuitive--you're making something that wants to be big into something very small. You're adding growth, but taking most of it away. You're hoping for dense roots, but remove them in order to renew them ( I wonder what mast Shigo would say about root pruning...he would undoubtedly shriek and turn very pale if you described the practice. He might even expound on how undignified it is).

 

[Mortalis]

So, our response to Dr. Shigo would be:
Respecting a tree would mean that we leave it to become what Nature intended it to be, but as a bonsai, it is nothing but a live medium that we try to manipulate.
Would that be a reasonable response?

I Respect my trees greatly in fact I love them. I had my dogs fixed, and I trim their claws. Some people cut their ears and tail. You would not do this to a wolf but We over generations by selective breeding change wolves into dogs. I still respect them.

I myself "mutilate" my own body with Tattoos and piercings. I still respect myself.

We over generations select trees with characteristics we want then clone them with cuttings.

At its most basic a trees existence is to live and continue its genetic line. I would say very likely all of my trees are clones from other trees and that continues those trees existence. I try my hardest to keep them healthy. I simply want to make them beautiful.

 

[Attila Soos]

I Respect my trees greatly in fact I love them. I had my dogs fixed, and I trim their claws. Some people cut their ears and tail. You would not do this to a wolf but We over generations by selective breeding change wolves into dogs. I still respect them.

No doubt, respect means different things to different people.
To many, respecting animals mean to leave them in the wild, roaming free. To them, the Zoo is a terrible thing.
But the zookeepers respect the animals just as much, and they spend their lives caring for them.
This difference will never be solved, but that's life. All we can do, is to present a good argument for, or against it, depending on what we believe in.

To me, respecting the tree means that I work WITH the tree and make sure that after occasional "procedures", it is always restored to good health and beauty.

 

[Attila Soos]

A lot of hand wringing over something that is not really pertinent. Yeah, large cuts on big trees can kill them. So can large cuts on small trees. You do it as carefully as you can. Hope for the best.

If you start overthinking, worrying about stuff that doesn't really happen (when's the last time you lost a tree to a trunk chop? I have NEVER lost a tree from any drastic pruning. All the trees that I've lost have been the result of some kind of root or soil issue.

As for Shigo, who really gives a damn. I get rather tired of him and his acolytes...He's not doing bonsai, and it appears that he doesn't approve anyway. Bonsai can add dignity to otherwise boring, or even ridiculous trees.

Trees have no diginity, other than that which we impose on them. Trees can't choose how they're wounded in the wild. They adapt and survive Nature's rather imprecise and mostly undignified treatment. They've been doing that for a VERY VERY VERY long time, despite Mr. Shigo's best intentions.

That's the spririt, I like it! It instantly makes me feel better.

And for what it's worth, bonsai is just a big set of contradictions. It's enormously counterintuitive--you're making something that wants to be big into something very small. You're adding growth, but taking most of it away. You're hoping for dense roots, but remove them in order to renew them ( I wonder what mast Shigo would say about root pruning...he would undoubtedly shriek and turn very pale if you described the practice. He might even expound on how undignified it is).

No wonder people are confused.

Talking about root pruning, I was also thinking what Dr. Shigo would say about creating a Shari, Jin, or God forbid, a Hollow Trunk. I don't even want to go there.

 

[Mortalis]

I think Dr. Shigo most likely mowed his grass and pulled weeds. Why is that ok.. Why can I freely disrespect grass and weeds?

Because they are not as beautiful.

My wife will tell me to kill a roach but not a ladybug.
You will eat a catfish but not an angel fish.
You can kill a cow but not a baby seal..
and so on.

We try to keep our trees alive we want them to do well. We want them to be the best they can. We want them to continue after we are gone. Don't you have someone in mind to care for your trees after your dead? That is respect.. to care about something enough to want it to continue to be even after you can no longer enjoy it.

 

[mcpesq817]

I'm confused - can I mow my grass and trim my shrubs?

 

[Mortalis]

I'm confused - can I mow my grass and trim my shrubs?

No no never!!

 

[greerhw]

Dr. Shigo, good movie.

keep it green,
Harry

 

[Attila Soos]

I'm confused - can I mow my grass and trim my shrubs?

Joking aside, Dr. Shigo, as I understand, would perceive in a negative light an action that permanently harms a tree. Mowing grass, or pruning a hedge does not permanently harm them, it rejuvenates them. They recover 100%. On the other hand, when the trunk of of a tree is partially killed, that will be perceived by some (not necessarily the bonsaist), as harming the tree. That's because the dead part will never heal. It will just be sealed off from the live portion. As long as this happens over a relatively small area, the tree is not in danger. As the are increases, the defense system may be pushed to the limit.

 

[Attila Soos]

Dr. Shigo, good movie.

keep it green,
Harry

Omar Sharif plays Dr. Shigo?

 

[greerhw]

Omar Sharif plays Dr. Shigo?

You nailed it.

keep it green,
Harry