Cutting back oak

[Menchhofer]

Received a call from customer. She has been told by two other arborists that her oak tree (100 yrs old or so) needs to have 1/3 of the crown removed due to their driveway installation 10 years ago. The drive was gravel, but changed to asphalt a few years ago. The tree evidently is in the center of a circlular drive.

The tree crown now contains numerous dead limbs (really?). The arborists are telling her when the tree is cut back, the root system will shrink thus solving the problem with the driveway proximity to the tree. The cut back "will also help distribute needed nutrients to the remainder of the tree".

I seem to be fighting an uphill battle on this one as she has two opinions quite the opposite of mine. What say you ?

 

[mckeetree]

Received a call from customer. She has been told by two other arborists that her oak tree (100 yrs old or so) needs to have 1/3 of the crown removed due to their driveway installation 10 years ago. The drive was gravel, but changed to asphalt a few years ago. The tree evidently is in the center of a circlular drive.

The tree crown now contains numerous dead limbs (really?). The arborists are telling her when the tree is cut back, the root system will shrink thus solving the problem with the driveway proximity to the tree. The cut back "will also help distribute needed nutrients to the remainder of the tree".

I seem to be fighting an uphill battle on this one as she has two opinions quite the opposite of mine. What say you ?

I say the two other arborist are a little off base.

 

[Tree Pig]

Received a call from customer. She has been told by two other arborists that her oak tree (100 yrs old or so) needs to have 1/3 of the crown removed due to their driveway installation 10 years ago. The drive was gravel, but changed to asphalt a few years ago. The tree evidently is in the center of a circlular drive.

The tree crown now contains numerous dead limbs (really?). The arborists are telling her when the tree is cut back, the root system will shrink thus solving the problem with the driveway proximity to the tree. The cut back "will also help distribute needed nutrients to the remainder of the tree".

I seem to be fighting an uphill battle on this one as she has two opinions quite the opposite of mine. What say you ?

Whats your opinion?

____________________


First I must say I am not an Arborist nor an expert but my opinion is that even though they may not be 100% I dont think they are that far off base. Selective thinning will help the tree equally distribute its nutrients. I am not all that sure on the roots shrinking back but some thinning will help keep the crown to a level that matches the root system (if the root system is limited). Dying limbs is inevitable even on a healthy tree as the inner limbs fight for sunlight the tree will let them die and redistribute the nutrients. Depending on the damage to the root system and the size of the tree there may come a time were keeping a healthy attractive tree may be too much to ask.

But again I may be off base on this too.

 

[treeseer]

no pics no useful advice, just speculation.

Removing live branches that are in decline may be warranted, if a more vigorous "inner crown" is the goal. Removing 1/3 of the healthy branches would not be good.

If root damage is the problem, and all you think about is what branches to cut, aren't you forgetting something?

:monkey:

 

[John Paul Sanborn]

It is a mature oak that is in a circle driveway which had construction work 10 years ago, and is now showing significant decline.

My response would be that the root lass has already occurred and the tree is trying to compensate for that, so, if it is not already in the classic death spiral, then a 1/3 reduction of live tissue would more then likely precipitate that.

I thought that pruning to influence root:shoot ratios was thrown out years ago?

A drive encircling it would have effected a significant percentage of the root plate and absorptive roots. Do the math to show the effected area, and say that you feel that you need to stimulate fine root growth.

My prescription would be;

• hazard deadwooding
• now N fert
• root stimulation
• paclob. treatment to keep fert from causing a flush of sprouts.

I would tell the prospective client that it may be too late to save this tree, but that we can put it in long term care. The root loss to date may already becoming root rot that will require removal at a later date. The proposed regimen may help reduce the chance, or prolong the inevitable removal.

Since terminal buds produce hormones that stimulate root growth, the removal of these buds has been shown to stop the replacement of the ephemeral absorptive roots, furthermore stress hormones seem to direct more energy reserves to sprouts that will replace the loss of photosynthetic mass.

 

[mckeetree]

It is a mature oak that is in a circle driveway which had construction work 10 years ago, and is now showing significant decline.

My response would be that the root lass has already occurred and the tree is trying to compensate for that, so, if it is not already in the classic death spiral, then a 1/3 reduction of live tissue would more then likely precipitate that.

I thought that pruning to influence root:shoot ratios was thrown out years ago?

A drive encircling it would have effected a significant percentage of the root plate and absorptive roots. Do the math to show the effected area, and say that you feel that you need to stimulate fine root growth.

My prescription would be;

• hazard deadwooding
• now N fert
• root stimulation
• paclob. treatment to keep fert from causing a flush of sprouts.

I would tell the prospective client that it may be too late to save this tree, but that we can put it in long term care. The root loss to date may already becoming root rot that will require removal at a later date. The proposed regimen may help reduce the chance, or prolong the inevitable removal.

Since terminal buds produce hormones that stimulate root growth, the removal of these buds has been shown to stop the replacement of the ephemeral absorptive roots, furthermore stress hormones seem to direct more energy reserves to sprouts that will replace the loss of photosynthetic mass.

I was experimenting with paclobutrazol before it became a household word and found it is best to do the growth regulator first and then follow with your slow release a year or so later. Paclobutrazol can be tricky on declining trees and I always adjust the dose accordingly. And I think you are right, pruning live wood to influence root/canopy ratios is old science.

 

[John Paul Sanborn]

I know a couple of people here who are having good results incorporating low N broad spectrum ferts. Whenever I speak of fert, I am not talking of a commercial NPK product.

I probably should elaborate on that ,since there are people who have not seen my diatribes on commercial fert.

 

[Menchhofer]

It is a mature oak that is in a circle driveway which had construction work 10 years ago, and is now showing significant decline.

My response would be that the root lass has already occurred and the tree is trying to compensate for that, so, if it is not already in the classic death spiral, then a 1/3 reduction of live tissue would more then likely precipitate that.

I thought that pruning to influence root:shoot ratios was thrown out years ago?

A drive encircling it would have effected a significant percentage of the root plate and absorptive roots. Do the math to show the effected area, and say that you feel that you need to stimulate fine root growth.

My prescription would be;

• hazard deadwooding
• now N fert
• root stimulation
• paclob. treatment to keep fert from causing a flush of sprouts.

I would tell the prospective client that it may be too late to save this tree, but that we can put it in long term care. The root loss to date may already becoming root rot that will require removal at a later date. The proposed regimen may help reduce the chance, or prolong the inevitable removal.

Since terminal buds produce hormones that stimulate root growth, the removal of these buds has been shown to stop the replacement of the ephemeral absorptive roots, furthermore stress hormones seem to direct more energy reserves to sprouts that will replace the loss of photosynthetic mass.

JP

My thinking mirrors what you have stated. More than likely the tree has already begun the downhill slide. Such a situation would involve long term care w/no guarantee of the tree's survival.

I compare this tree to a large battery. There is only so much juice available for it to continue growing and now it's re-charging ability has been damaged.

 

[treeseer]

My prescription would be;
...
* root stimulation

What doe sthis mean, big guy? poke the roots with a stick?

 

[John Paul Sanborn]

My prescription would be;
...
* root stimulation

What doe sthis mean, big guy? poke the roots with a stick?

Tickle with a feather

products that promote fine root development, the seaweed sauce I've used in the past seems to do that, as advertised. Pan-A-SeA by Emerald Isle.

I've seen others advertised for the same purpose, also.

 

[Boa07]

When I was working hands on and sweaty in transplanting we used to apply a dilute combination of both seaweed extract, fish emulsion black strap molasses humic and fulvic acids, we found as you describe great results both short term 2-4months and longer term 2-4yrs.

Oddly the more dilute the mix (within reason) the more immediate the visual results.

 

[John Paul Sanborn]

Oddly the more dilute the mix (within reason) the more immediate the visual results.

Could be that it is more available, and you do not have a confouncing effect of the sugars drawing water out of the tissue before the tree can use it.

I know I can be more precise, something about osmosis and sugar being hygroscopic, but I'm over caffeinated right now and cannot think straight drug abuse!

 

[Boa07]

I think you are right JPS, I still enjoy the disbelief on peoples faces when you tell them to use less not more.

 

[John Paul Sanborn]

I think you are right JPS, I still enjoy the disbelief on peoples faces when you tell them to use less not more.

I also find it interesting the things that are turning up in research the past few years: how sucrose is a stress signal chemical, possibly a response from hone dew secreted (or is that an excretion?) from sucking insects. It induces a thicker cuticle and and phytotoxin production in some plants.