The art of crown reduction...

[logantree]

I've got a customer with a rather large oak that they want crown reduction performed on. (I'm not exactly sure what kind of oak it is, having some trouble identifying what kind of oak it is. Has a crown a lot like a pin oak, but leaves more like a red oak.) I've looked the tree over and trying to figure out where to cut it back. I've read the BMPs, and the Certification Study Guide, and feel like I have a pretty good understanding as to a proper reduction cut. My big problem is that it looks a lot better on paper than in the tree. I know there has to be an art to it. I'm sure it just takes a lot of practice, and that's something I don't have a lot of in crown reduction. In a lot of the trees that I've looked at just trying to figure out where I would cut it back, it seems that the lateral you're cutting back to is in a lot of cases as long as the limb you're cutting. I guess you then just have to trim the limb you're leaving back as well?

I've ordered Ed Gilman's Illustrated Guide to Pruning, and hope to learn something from that. Can y'all give any advice/tips?

Thanks in advance for your help.

Regards

 

[D Mc]

You seem to understand your limitations and that is a good first step. Gilman's book has a lot of detailed information. Perhaps a picture would help us help you. Aside from your learning how to properly reduce a tree, I would want to know why the homeowners want this particular tree reduced. When a client asks for a reduction, we always ask why so that we understand their goals. Their goals may not match their terminology.

Dave

 

[logantree]

I'll see if I can get a picture for you...

They want it reduced because it's standing pretty close to the house, and starting to touch the roof. The tree is pretty large at the trunk (maybe 24-28 inches), but not very tall (maybe 35-40 feet). It has a very nice shape at the moment, but I think that trimming the one side back a bit would look odd...I could be wrong though. (It's happened at least once before.)

 

[treeseer]

They want it reduced because it's standing pretty close to the house, and starting to touch the roof.

Well then they need some branch reduction, and not an overall crown reduction (which is seldom needed and easily overdone in a young oak).

 

[tree MDS]

I thought crown reduction was something more typically performed in tropical areas (where trees are rooted in sand primarily), mainly to reduce wind sail during hurricane season??

 

[John464]

Well then they need some branch reduction, and not an overall crown reduction (which is seldom needed and easily overdone in a young oak).

if an owner desires the tree to maintain a certain height/spread it is much more desirable for the tree to be trained and contained in a younger non mature tree. These are the customers I love. A bi-annual pruning/reducing miantenace plan is quite acceptable, but not so for a mature tree. I think you meant to say an old oak, rather than a younger oak?

 

[John Paul Sanborn]

Large old trees can easily be over pruned and set into Shigo's Death Spiral.

Older, healthy trees are in a dynamic equilibrium; they put on around the same dynamic mass as they shed, maybe a little more. By over pruning we take all this photosynthetic material away; thus forcing new growth which depletes reserves that will never be replaced.

I would agree with a selective limb reduction to mediate any damaging contact with structures, but crown reductions due to height alone is not good for the tree.

Quite often the height issue is a false economy, because the low limbs will catch any higher breakage that will have force of impact on a roof.

 

[teamtree]

I have read up on proper crown reductions and talked to many CAs about it and used those techniques and I have found it is a fine line between making the right cut and making the wrong cut as to the effect on the tree. The best advice I can give, take less rather than more and always leave a lateral >1/3 the size of the limb being removed.

 

[John Paul Sanborn]

The best advice I can give, take less rather than more and always leave a lateral >1/3 the size of the limb being removed.

This is only if you are doing one or tow branches, if you are working the entire tree like this....

 

[treeseer]

... The best advice I can give, take less rather than more and always leave a lateral >1/3 the size of the limb being removed.

Why 1/3?

opcorn:

 

[Rickytree]

Why 1/3?

opcorn:

So the tree can heal over the wound and so there is a place for the energy of the tree to travel.

 

[treeseer]

So the tree can heal over the wound and so there is a place for the energy of the tree to travel.

Couldn't that happen if it was 1/4?

I wonder where the 1/3 rule came from,

 

[ddhlakebound]

Couldn't that happen if it was 1/4?

I wonder where the 1/3 rule came from,

Each branch needs to maintain a minimum percentage of foliage for several reasons. (doesn't it?)

to reduce the probability of dieback.

to reduce the aventitious sprouting response.

so that the limb can produce enough energy that draws less from the trees reserves, or produces enough energy to support it's own sealing and compartmentalization.

that is appearance is more natural and aestitecally pleasing


And for this tree specifically.....now is not a good time to be wounding red oaks if oak wilt is present in your area.

 

[D Mc]

I wonder where the 1/3 rule came from,

An Illustrated Guide to Pruning, Second Edition, by Edward F. Gilman
Chap 5, Page 56, "Reduction Cuts: A reduction cut reduces the length of a stem or branch by removing the terminal portion back to a branch or lateral of equal or smaller diameter. The cut is made to a living side (lateral) branch that is large enough to assume apical dominance. This size varies with species, but should be at least 1/3 (minimum) to 1/2 (preferred minimum) the diameter of the cut stem."

Best Management Practices - Pruning, Edward F. Gilman and Sharon J. Lilly, Pg 21 "Reduction Cut:...A common rule of thumb is that the remaining lateral branch should be at least one-third to one-half the diameter of the removed portion."

Do I agree? I view these as guidelines rather than rules. There will always be exceptions, as in most everything we do.

Dave

 

[Rftreeman]

Couldn't that happen if it was 1/4?

I wonder where the 1/3 rule came from,

I was always taught the 1/3 rule.

 

[treesandsurf]

Crown reduction is an art that is easily blotched. :monkey:

I've seen very few good examples of proper crown reduction; very difficult to achieve (especially with certain species) and still have an appealing and relatively undamaged specimen at the end of the day.

We do them every once in a while for views but only with certain species. Some species here in the tropics just do not give you the option to do crown reductions. For some reason, many homeowners believe that regular maintenance of a tree should always include reducing the height .

jp

 

[treeseer]

An Illustrated Guide to Pruning, Best Management Practices - Pruning

Yeah I know the 1/3 rule is written there and elsewhere, and Rf I know we were all taught it, but I just wonder if it has any scientific basis.

Jon where did that graphic come from?

Does crown cleaning involve removing live branches?

Doesn't crown reduction include reducing width as well as height?