Long stub or no stub

[Knapp]

It is looked on as bad practice to leave a long stub when removing a branch. To do so invites rot into the trunk because occlusion cannot occur.

 

When a tree looses a branch naturally it will often leave a long stub and if that branch has a large diameter then umpteen years could pass before occlusion can even begin. Does rot pass into the trunk or does it depend on the species?

 

Is it just neatness to trim back to the branch bark ridge or is the tree not worried either way? A conventional neat cut would be unknown in tree evolution.

 

Maybe the long decaying branch gives a tree time to set up decay barriers and very large diameter branches that will never be occluded, may get decay into the trunk quicker when cut back to the bark ridge than if left long.

 

Any thoughts on this?

[Lorry thompson]

I have wondered this myself for years will be an interesting thread, along the same lines I also wondered when working on a tree that already has a dead branch is it better for the tree if you leave it or if you prune it will this encourage the tree to "seal" the area?

[skyhuck]

The tree has no way of removing the stub once a branch has been broken off by the wind or some other cause.

 

If the tree kills of a branch, as its no longer efficient due shading or like, the branch dies at the collar and then over time the branch drops off leaving no stub.

 

When removing large branches, too large to be sealed within a time frame that will not allow excessive rot. It generally considered bad practice to take it right back to the trunk, its better to cut back to a growth point or even Pollard the limb.

[Arborowen]

When you see, for instance dead wood remaining on an oak, occulsion can be seen to be occouring but is not able to seal the wound completely due to the remaining obstruction.

 

In this instance the tree will rely on the remaining fail safes which are Shigos 4 'walls'.

 

In an ideal world the would would seal to prevent the entrance of moisture into the wound this as we often see in nature this doesn't always happen. i'm a firm believer in the fact that, as arborists/tree surgeons we can give the tree the best chance of sealing a wound quickly/efficiently by carrying out effective and professional finishing cuts.

[Arborowen]

The tree has no way of removing the stub once a branch has been broken off by the wind or some other cause.

 

If the tree kills of a branch, as its no longer efficient due shading or like, the branch dies at the collar and then over time the branch drops off leaving no stub.

 

When removing large branches, too large to be sealed within a time frame that will not allow excessive rot. It generally considered bad practice to take it right back to the trunk, its better to cut back to a growth point or even Pollard the limb.

 

with specific refference to a "wound being to big to seal in the time frame" what do you mean?

 

I have seen in many instance strong occluders like Platanus etc occulude rediculously large wounds. by time frame im guessing you mean, that by the time it has acheived complete occlusion significant exposure to moisture has occoured. in this instance i think the tree would again rely on its fail safes, (shigo's walls), some decay may begin to occour within that wound but it wont get far, (obviously this depends on species, conditions, resources and surrounding area).

 

Trees live whitin far greater time-scales than our own, what to us could appear as 5 years of wet, open wound doing damage is barley a week in the life of a tree. And i bet that they are willing to 'sit out' the bad times

[blazer]

With most of the oldest Oaks being 'pollards', I assume axe cut in cycles for hundreds of years. Then Oaks can cope with big boughs being removed and not affecting the trees health.

 

But from clearing alot of fallen Oak boughs which mainly have some fungus damage I assume the tree rejected them naturally in the next storm.

[Ben90]

Is it just neatness to trim back to the branch bark ridge or is the tree not worried either way?

 

Am I the only one who noticed this? This isn't the 70s my friend, flush cuts are sort of frowned upon. I think you mean just beyond the branch collar.

 

Many here including myself believe that stub cuts are a great way of helping the tree to compartmentalise and partly occlude, especially since the branch we're removing is more often than not, alive. The tree then has time to set up it's defensive barriers on the branch that it had no intention of killing off naturally, and (if practical) you can return in a year or so's time to carefully remove the stub back to the perfect point, because the branch collar will have swelled by then giving you a perfect line to cut.

 

Of course, who would add a re-visit to the bill for every job to remove stubs? Nobody.

Edited October 13, 2010 by Ben90

[skyhuck]

with specific refference to a "wound being to big to seal in the time frame" what do you mean?

 

I have seen in many instance strong occluders like Platanus etc occulude rediculously large wounds. by time frame im guessing you mean, that by the time it has acheived complete occlusion significant exposure to moisture has occoured. in this instance i think the tree would again rely on its fail safes, (shigo's walls), some decay may begin to occour within that wound but it wont get far, (obviously this depends on species, conditions, resources and surrounding area).

 

Trees live whitin far greater time-scales than our own, what to us could appear as 5 years of wet, open wound doing damage is barley a week in the life of a tree. And i bet that they are willing to 'sit out' the bad times

 

I'm talking about limb removal wound that may take 20, 30, or more years to seal. I have seen hundreds of trees with huge wounds that have rotted back creating massive cavity's, IMO, it would have been better to have cut back to a growth point, instead of the stem, even polarding the limb is preferable to a huge wound.

[Knapp]

Ben90; your'e right I did mean branch collar.

 

What made me think about this was seeing the work done by British Waterways on the canal. A lot of the overhanging branches from set back trees were cut back only as far as the canal boundary, which meant a lot of long stubs were left.

 

This set me wondering about how rot enters a tree and what happens when occlusion is prevented by the presence of a stub.

 

Thanks for your interesting replies everyone.

[Ben90]

What made me think about this was seeing the work done by British Waterways on the canal. A lot of the overhanging branches from set back trees were cut back only as far as the canal boundary, which meant a lot of long stubs were left.

 

That's just bone-idleness. No consideration for the trees there or even their own jobs, since new stems will probably shoot from the cut and won't have to go far to get straight back over the canal.

 

Probably a boundary related issue, the trees are grown on council land and the branches overhang BW land. They're only entitled to remove what's overhanging.