Case study

[ATH]

I do find your selection of cuts interesting. I would have leaned towards taking the more horizontal shoots off rather than the vertical ones, just to keep them from reaching as much over the life of the tree. Is my gut wrong/ can you explain for my benefit why you would make those where you drew them?

Edit: I totally get the left one. My question is more for the other two, and especially the right one.

First...remember, this is a first pruning with plan to return in 5 years. But, yes, there are reasons to take the more vertical and leave the more horizontal:
1) When trying to establish/distinguish a dominate leader from 2 co-codoms I want as much sunlight as possible getting to that leader. Anything that will be shading it between now and the next pruning cycle goes (ideally...not always possible).
2) Horizontal limbs take more downward force to break them than vertical limbs. Without typing an essay, here are a few thoughts on that. Vertical limbs are made up of primarily "normal wood" while horizontal limbs have much more reaction wood. That reaction wood is stronger because they have to fight every day to stay up. A vertical limb sees relatively little stress until the wind blows. Often that is not frequently enough for adequate reaction wood such that when a big wind blows, it hasn't strengthened itself enough to hold. The stronger trees tend to be the excurrent branching trees while the decurrent branching trees tend to fall apart in storms more frequently. You want to encourage wider open angles to encourage stronger branching. Obviously, you don't want to make a lion's tail in the process... As far as the tree is concerned, there is almost no such thing as "over extended branches" - they'll go where they can get the most sun and build the wood to support it. If it is getting too hard to do that, they'll stop growing longer and just keep adding diameter. Just ask a Live oak.

 

[colb]

Curious...which are you looking at as the weaker leader? Feel free to argue, as I've argued with myself

Yes, white oak are stronger than most....but a co-dominate leader with included bark will still be the weakest point of the tree and prone to failure during a storm. Especially as the "lever" pulling at the defect gets 40' longer in the future.

Haha, a little unfair because I've seen the tree and you haven't.... Appreciate you jumping in and I'm paying attention. The three leaders are, practically, the same size. The rear one going towards the house may be slightly larger, but there is some serious codominance between these leaders. Nice thing is, one can chose a leader - no shortage of options. The leader near the other trees is messing with the small white oak, which is additionally suppressed by lower limbs on the big white oak. I want the small white oak to establish in that space, and it needs help. (Additionally, the small white oak has three branches, two of which are crossed up, necessitating a removal prune/retrenchment prune...) I thus want the tree-side leader of the big white oak to be subordinate to the driveway-side leader, which has great access to sunlight and no targets to fall on. Get me?

Also, not sure if you can see it but I reduced an over-extended house-side branch on the red oak that shares a base with the hickory. Three cuts there, in 1.5-3" wood, using my echo cs2011t for the first time.

 

[colb]

@ATH noting that we have differing opinions about overextension while we're writing at the same time...

 

[ATH]

I want to establish the fork going away from both the house and the other trees (and going towards the driveway and road) as the primary leader. ....

I get that - which was the reason for my first "pruning" cuts. But if it were a strong single well-centered trunk established from a dominate leader its whole life would you even think twice about it? I wouldn't - I'd leave the tree alone. My 'argument' with myself is "can you make it look like that?" and if so which leader is most likely to be that in the long-term. That is the left one. If we can make that a balanced, central leader then it doesn't matter which side of a codominate fork it used to be on. Food for thought. Again...not saying one is right or wrong. I am undecided, just talking through my thought process. Hopefully that is the goal here. Good thread. I have one of my own from a visit today that I'm going to start.

 

[ATH]

@ATH noting that we have differing opinions about overextension while we're writing at the same time...

I don't disagree that there are branches that need pulled back...but needing pulled back because they can't be supported is rare. Pulled back because they are contacting the roof (or will be soon) is another question! Also, Frank Rinn got me to thinking about pulling back unbalanced (OK....fine, call them overextended!) limbs to reduce torsional stress on a tree. If it is excessively long on one side that will cause more twisting on the trunk, which trees are not well suited to deal with.

 

[Leroy]

SDS with toxicology info first. Then some state govt analysis, then a study/review or two I think.

Well.... shit, you got me there. Clearly I just linked the article that supported my gut reaction.

I am born again chemi-phobic, I just don't trust it!

 

[JD3000]

Dude, my in-laws have been here since 430 and I'm losing it. I'm heading to your place now.

I prefer waffles.

 

[JD3000]

Do you see more horizontal branch failure? I do when their very end heavy but not too much otherwise. Lots of reaction wood as ATH mentioned. I generally see more uprights on softer wood trees snapping off.

As well as co-doms with inclusions of course.

 

[JD3000]

What trees? Over pruned with lots of end weight?

 

[JD3000]

And get yerself a proper ridiculous avatar damnit.

 

[SomethingWitty]

I hadn't figured out which one was stronger. It's just a picture.
I appreciate the explanation, and I have to say that I remember most of it from studying.
I think my inclination is from pruning a lot of mature trees with old wounds and poor unions. Reducing leverage by shortening the levers in the outer canopy has been a lot of my career. I have recently done more early training, and I will try to keep in mind the differences. I think I will try to read more as well.

 

[ATH]

I see horizontal branch failure on lion's tailed trees... We don't get enough big snow loads or ice loads to see frequent failures. Most of the time it is pretty predictable stuff when it does happen. In an area that regularly gets those loads, especially on trees that are not well adapted, there is probably some logic to pruning to minimize leverage. But in most cases, I'm still convinced the tree "knows" what it is doing when it engineers long branches. People ask about those and my usual response is "why isn't there a swing hanging from that long horizontal branch?"

About 15 years ago, Shawnee State Forest in southern Ohio got hammered...HAMMERED by an ice storm. I went down as a forester to help access the damage - our goals were to map the extent of it and get some idea of volume of downed timber (there was a lot- I wanna say 5-6 MMBF, but I think that is too low...that might be all there were able to salvage?). Entire hillsides of mature oaks uprooted. I wish I could revisit that situation as an arborist and spend more time looking at branch failures. Hope that never happens again, but I would enjoy making those observations.

 

[colb]

I get that - which was the reason for my first "pruning" cuts. But if it were a strong single well-centered trunk established from a dominate leader its whole life would you even think twice about it? I wouldn't - I'd leave the tree alone. My 'argument' with myself is "can you make it look like that?" and if so which leader is most likely to be that in the long-term. That is the left one. If we can make that a balanced, central leader then it doesn't matter which side of a codominate fork it used to be on. Food for thought. Again...not saying one is right or wrong. I am undecided, just talking through my thought process. Hopefully that is the goal here. Good thread. I have one of my own from a visit today that I'm going to start.

Great post. Totally get what you're saying.

 

[JD3000]

Alright, if you remove one co dom at the fork and its a big diameter cut, do you remove or reduce any more?

 

[JD3000]

Here is a good example albeit shaky footage. The first failure is a green ash co-dom situation. Second is a large horizontal in a honey locust.

Never liked the structure on many a green ash. Talk about overextended limbs prone to shear plane fracture

 

[colb]

Word, torsion fractures are real! I must say though, we often reduce horizontal limbs to minimize leverage and surface area with the intention of reducing failures in early or late snows. What do you make of this?

My problem with reducing horizontal limbs is that they can get shaded into decline by the limbs atop them. I tend to reduce the whole area, then prune trans to rebalance the tree...

 

[JD3000]

Good way to establish your lowest permanent branches though. Keep the low ones subordinated and they wont increase diameter as much so your wound is smaller when they're removed eventually.

 

[colb]

I see horizontal branch failure on lion's tailed trees... We don't get enough big snow loads or ice loads to see frequent failures. Most of the time it is pretty predictable stuff when it does happen. In an area that regularly gets those loads, especially on trees that are not well adapted, there is probably some logic to pruning to minimize leverage. But in most cases, I'm still convinced the tree "knows" what it is doing when it engineers long branches. People ask about those and my usual response is "why isn't there a swing hanging from that long horizontal branch?"

About 15 years ago, Shawnee State Forest in southern Ohio got hammered...HAMMERED by an ice storm. I went down as a forester to help access the damage - our goals were to map the extent of it and get some idea of volume of downed timber (there was a lot- I wanna say 5-6 MMBF, but I think that is too low...that might be all there were able to salvage?). Entire hillsides of mature oaks uprooted. I wish I could revisit that situation as an arborist and spend more time looking at branch failures. Hope that never happens again, but I would enjoy making those observations.

I'm not personally a fan of the trees "knowing" hypothesis. Organisms are generally optimizing for current conditions, not average current conditions, or 10-year average current conditions. They just go in the here and now until they cannot.

 

[JD3000]

I think he meant that many a long branch sets plenty of reactive wood to compensate for its own weight.

 

[colb]

Alright, if you remove one co dom at the fork and its a big diameter cut, do you remove or reduce any more?

Yes, but it's a *lot* of intense structural and aesthetic pruning, probably over 2-3 growth seasons. Aesthetically, it would take at least 4 years to recover, I think... The upsides are that I would not cable and brace it, and the tree would have established lean away from the house. A lot of peace of mind, longterm...