Pruning Paradigms: Eternal Truth?

guymayor

guymayor

Branched out member
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East US, Earth
http://tcia.org/digital_magazine/tci-magazine/2013/10/index.htm#?page=46

The author is a gifted authority on shrub pruning but with trees it's all about the 1/3 rule, The Heading Cut Concept. However, this falls apart when you think about it.

No one can answer the question: Is it really important to leave a lateral that can assume the terminal role? If so, why?

What if there is no 1/3 sized lateral? Do you have to cut back to a small lateral or bud, or do you have to cut the whole tree down? Turnbull favors the latter, destroying the tree asset rather than questioning this paradigm. Is that the right thing to do?
 
Guy I think it depends on the tree..........and a lot of different factors about each particular tree. When I worked on the west coast it really had me up in arms when I saw 8" dbh eucs lopped back to nothing by knowledgeable arborists???? (and I mean just the trunk was left. Trees with no branches for 9/10s of their height then a narrow fork with inclusion lopped back to....nothing? 20 years later they look surprisingly decent....trained over the years by the same arborist. It must've been a bottomless tree budget :)
 
Aesthtically it looks much better and also allows a larger area of adjacent plant chemicals to pull from to seal the wound as well as allow the movemnt of plant growth regulators to move away and to the area to avoid sprouting.

The right thing to do is to understand all these concepts and opinions with this regard and apply it the best you cna to the tree you are working on.

My thoughts in pruning a tree are focused primarily towards the same goals in Young Tree training.

Crown reductions consider tree yrs and what the client wishes

I like to preserve trees even if it means topping cuts. Managing the liability and mitigating the hazards is hard work both acedemically and practically.
I love being an arbclimber and pruning over removal is what makes me feel good at the end of the day. Just my opinion and changes from day to day and tree to tree.
smile.gif

Cheers and happy Sunday guys.
 
I think it's important to remember that we all start somewhere in this industry. Rules of thumb like the 1/3 rule give beginning Arborists something to work with since they lack the experience to throw out the rule book and follow their own knowledge and intuition. If you really want to toss out some of these rules, come up with something better but keep in mind that the future of Arboriculture is not Arborists with 30 years of experience, but the 18 year old kid who was just hired on as a groundman.
 
I don't think it necessarily "falls apart when you think about it" at all! While we can all appreciate the significance and beauty of old "historic" trees, I agree with Shigo that a tree can eventually "lose it's dignity". It's replacement (for future generations to appreciate) might be in the greater long-term public interest than "retrenchment" options.

I think the title of the thread Pruning Paradigms: Eternal Truth?" is a tad misleading, or intended to inflect a possibly negative slant on a thought-provoking and well-written article by C. Turnbull. I would expect such from the OP whose livelihood is somewhat dependant on the preservation of geriatric patients; whatever the cost, whatever their condition!
 
Thanks guys; I admit my preservationist bias, as that fits my definition of what an arborist is, and my clients' goals. Points taken about rules of thumb for beginners, and the need to come up with something better!

But the recommendation of remove-and-replace is way too casually tossed out imo instead of setting aside that rule of thumb. Way too many perfectly viable trees lost that way.
 
I AM with you Guy... actually probably swng further in your direction than even you are..
On the road, so I didn't get a chance to read the whole article and initial impression is that I disagree with the "logic" presented in the article. Will read it and reply.
 
"OK,
I read the article. The author obviously put a lot of time and energy into the writing and his care for trees and the industry shows.


Though I disagree with a lot of what he says and his "logic". I think those differences are primarily due to the differences in tree species and conditions on the west coast. I have never been asked to "top" a tree for view on the east coast. Though I know it happens all the time out west.. Especially with all those nice views of the water in Seattle.
That's just a small example of the types of differences that arbs face around the country. We need to understand that those differences can be profound! and try to get out of our limited perspectives and see it from the other guys POV. That said, the other guy should also recognize that there are big differences and make it clear that he is writing from his perspective, which will help the reader with that distinction.

Which gets us to the major problem with any tree standard. There are just too many variables to account for to make any quick and simple writing effective.
 
I think pruning standards (paradigms) are an excellent guideline to aim for. The author makes a strong case for making them all-encompassing "absolutes", even though some tree species, or individuals within a species (the "old, historically significant trees, for example) may merit exemption from established standards.
I don't have any more of a problem with the 1/3rd sized lateral than I do with "arbitrary" intoxication limits designed to weed out drunk drivers. Not everyone is influenced to the same degree by booze, so how come expert drinker/driver "X" gets the same treatment as "W, Y, and Z"? Shouldn't "X" be allowed to drink and drive, cause he is very good at doing both, has written extensively on the subject, lectured about same, etc? Plus, he has never killed anybody yet, nor wrecked his rare Lotus.
 
daniel,
the author of the article is cass turnbull - she's a she.
just fyi.
she's had a huge impact in these parts on the pervasive mis-information that trees "should" be topped. lotsa toppers still out there, but the public is much better informed thanks to cass.
 
Thanks for that info Kathy.

Its clear that Cass cares.. good that she cares enough to put the effort into that article..

HOWEVER... though the advice or perspective she presents in that article, may be sound for the type of tree work being done in Seattle, it does more harm than good (IMO) when dealing with Eastern hardwoods in suburban settings.. As Guy is pointing out as politely as possible. her logic falls apart quickly.. saying things like "shigo has shown that all reduction or heading cuts are harmful to trees"... That's a poor argument.. all pruning cuts to live limbs are harmful to trees.. the arbs job is to make the overall good done by the cut, outweigh the harm done.

I can make a much more sound argument in favor of reduction cuts on suburban hardwoods. Generally they are well used on long reaching horizontal limbs, which would otherwise be extremely susceptible to storm damage and summer limb drop.. While the damage done to a tree's health is minimal and the aesthetics are fine, with very little or no issues with sprouts.

And her suggestion that all reduction cuts should be lumped in with topping cuts, so as to keep the distinction that all topping are bad clear, just falls on its face, as soon as one can demonstrate a good use for reduction cuts.

Again, the difference in our positions are primarily due to the types of trees, their needs and the type of pruning done in Seattle vs East coast hardwoods. It would be good for her to make that clear, so when East coast arbs read it, they are not confused..
 
This is harder than I imagined. btw Daniel the author is a she. The whole idea of a standard is to allow specification writing to be as quick and simple as possible.

Pel, you'll need to read the standard to know it's NOT equivalent to the 1/3 Rule; your assumption is the same as the author's and it never was right, beyond a beginner's loose point of reference.

So if/when you read the standard you'll see the drunk driver analogy is whack.
 
Guy, I think the title you chose for this thread "Pruning Paradigms: Eternal Truth" was provocatively "strawmanesque". Eternal equates to something unchanging and perpetual. Since you are well aware that ANSI Standards are subject to periodic revision, are you perhaps concerned that these might instead become the equivalent of a Biblical injunction?

Second, the "if/when I read the standard" presumes a degree of ignorance on my behalf that I find rather unwarranted and offensive. You might/might not be quite surprised at both the quantity, variety, and quality of arboricultural tomes in my personal library.

Third, have you ever wondered why Ed Gilman wrote so little on "retrenchment pruning" in "An Illustrated Guide to Pruning, 3rd ed."? I have. I do agree with "It seems reasonable to keep reduction cuts less than 2 (weak compartmentalizers) to 4 (strong compartmentalizers) inches on most trees." (page 123)

I would most thoroughly enjoy listening to you and Cass debate your respective positions. And I think that as a BCMA, Cass is far more than "a gifted shrub pruner" lol.
 
Not suggesting general ignorance, just a painfully obvious unfamiliarity with the A300 standard. $15...

You nailed it re Biblical injunction; that's how many including Cass see the 1/3 Rule. Sad to be locked into a 1986 paradigm; the godfather would not approve.

The debate that you want would be very short. It's like talking to a fundamentalist zealot, or a wall.

btw, not that it matters a lot here, but there are no BCMA's --or even certified arborists!! --with that name; search for yourself. I guess when you're a local goddess those lesser titles mean nothing!

Not much retrenchment pruning for Dr. G to research in Florida. His work on reduction pruning with Grabosky though was quite noteworthy, would you agree?
 
Yes, quite noteworthy....like this sentence: "The data suggest that reduction cuts can be made back to lateral branches as small as one third the diameter of the removed stem" (Response of Two Oak Species to Reduction Pruning Cuts).y
 
That's an interesting conclusion.. given that the study draws such conclusions from the presence of discoloration, and in no way has any data on failure..

This is a paradigm problem that dates back to Shigo, whose initial research was for the forest service, the main focus of which was trying to preserve log value, by reducing discoloration.

As a suburban arborist, I couldn't care less about discoloration in a reduction cut. Take some weight of the branch tip and it won't fall on Mrs Smith's fence.. pretty simple really.. How much you can get away with taking is related more to the species response to pruning, rather than the presence of discoloration/decay.

discoloration/decay in a reduction cut is far different than in the main stem, where the presence of decay can cause catastrophic failure... Little common sense goes a long way..

Thanks for quoting that study... I found certain conclusions very validating, and busting another Shigo paradigm. The angle of the reduction cut does not effect discoloration and may actually better to make a smaller cut straight through the limb creates less decay than an angled (bisected) cut which leaves a larger surface area. Something I've been doing for years. The critics love to thump their Shigo bibles.. all you gotta do is open your mind and pay attention to what's going on out there.

This industry is really stuck!
 
Re: Pruning Paradigms: Eternal Truth?

Wow. Heavy duty. I wonder what she would think if i told her that sometimes i intentionally head back temporary limbs to encourage sprouting.
 
Re: Pruning Paradigms: Eternal Truth?

Daniel you're right about that conclusion; sticks out like a sore wishywashy thimb after the study. Demonstrates how 1 Conclusions are not data and 2 old myths die hard and 3 ya gotta slog through the body and not just cut to the finish. I had the chance to ask Grabosky about that wording and he struggled with a reply. Not even a guy with his considerable intellect and authority wants to contest that mythic ratio.

Spot on re: smaller cuts preferred, and the trouble with the 'bisecting angle' generalization. Species variability sends that one out of usefulness more often than not. The smaller the wound the better. Hard to argue with that.
 
Re: Pruning Paradigms: Eternal Truth?

Yeah....old myths die hard alrighty.
http://www.glte.org/sites/default/files/Dr._Coder__Arboritecture_Manual.pdf

"The stem - branch confluence selected as the reduction point should always have a lateral branch at least 1/3 the diameter of the stem to which it is connected" (page 47)

"Accumulation of heartwood exposures on pruning wounds can be devastating over time" (page66)

"Brutalizing a tree...is not acceptable" (page72)
 
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