Raisin Cain--Are we our branches' keepers?

[Guy Meilleur]

True or false:

"low branches are seldom appropriate for large growing trees in an urban environment...

street trees must be pruned so that they allow at least 16 feet for clearance...Most landscape trees only require about 8 feet of clearance.

Most large growing trees in the landscape must eventually be pruned to allow head clearance."

Quotes are taken from ISA's Pruning Young Trees brochure, seen at http://www.treesaregood.com/treecare/pruning_young.asp

The rest of the info in there I think is great, but the quoted assertions are not true according to my experience. They are excessive and lead to all sorts of problems, such as turfgrass outcompeting trees, and the senseless removal of the valuable lower canopy.

Do you agree or not? And if you think the above quotes are right, do you want to buy 100 brochures cheap?

 

[MasterBlaster]

I've done it to those specs many a time, for the city. I love it, it gives ME a chance to meet their specs, and make the tree happy as possible.
When others get the job, it generally looks pretty crappy.

Most of the time.

 

[jkrueger]

Would have agreed with you before today. Reading, PA, city trees have been a hot topic with me. The shade tree commission said they were agast that that the pub trans devision said all street trees were to be limbed to 16 feet.

Ho, ho, we all thought. Well, I had just cleaned, pruned and limbed up two Lindens for a city project presentation. Yikes, I went by today and a the lower street side limb was ripped off. Some delivery truck.

So, yes, for most high traffic city trees, 16 feet.

Jack

 

[Guy Meilleur]

Originally posted by jkrueger
So, yes, for most high traffic city trees, 16 feet.

Jack

Tractor-trailers are 13'6", aren't they? So isn't 14' enough? Then consider that most streets have parking places that are not occupied by trucks, so couldn't branches originate at <14' and then be trained to sweep upward?

And on non-street trees, do most of them really need to be raised to 8'? Why, is Yao Ming going to be wearing a top hat and walking up to every trunk?:blob6:

 

[geofore]

14'?

At 14', when it rains the limbs hang down and the next truck by takes them off. Ice or snow in the winter, addtional weight, limb hangs down and the next truck by takes it off. So much for 14' being enough clearance.

 

[MasterBlaster]

I like following the crane to the job. Watching it swerve into the oncoming lane to avoid limbs is a trip. If you didn't know better, you'd think he wuz drunk.

Public roads need to be cleared. Period. The only question is whether the tree trimmer knows what they are doing.

Or not.



Do it right the FIRST time, and be done with it.

 

[MasterBlaster]

I forgot a cool crane pic.

 

[Nickrosis]

Originally posted by Guy Meilleur
"low branches are seldom appropriate for large growing trees in an urban environment...

street trees must be pruned so that they allow at least 16 feet for clearance...Most landscape trees only require about 8 feet of clearance.

Most large growing trees in the landscape must eventually be pruned to allow head clearance."

I agree with the guidelines for street trees for the same reasons outlined above.

I disagree with the guidelines for landscape trees because there are many different scenarios. Yet someone reading this may apply it to spruce and pine trees and to trees that won't conflict with someone's head.

Pruning up trees for aesthetics or for protection from kids and vandalism are fine reasons but pruning just because or just to prune? No way.

 

[Stumper]

As a blanket generality I think that the guidelines are appropriate--BUT blanket generalities are inappropriate! Reality says that trees overhanging roadways need to allow sufficient clearance for normal traffic (at the very least). Our local Municipality specifies 12' over streets which doesn't make them Semi friendly but works for cars, pick-ups and most delivery vehicles. In the landscape it just depends. Lots of trees could be allowed to retain branches to the ground. In order to utilize the yard in other ways most people want to be able to walk under their larger trees. That doesnt require 8' but it does require pruning on many species. Most people want 8' at the tips so they can go a couple of years before the tips droop below 6'. So much depends on the situation-I've satisfied a lot of people by "raising " trees to 3-4 feet just so nothing hides in there.

 

[arboromega]

i used to do highway trimming for state contracts. trees were raised to 30 feet. well above any vehicle.

 

[Kneejerk Bombas]

Originally posted by Stumper
I've satisfied a lot of people by "raising " trees to 3-4 feet just so nothing hides in there.

You need to cut off all the branches that you can reach with your power pruner.
Three or four feet is not high enough. The things that hide in there might be bigger and bump their heads and sue you, so you have to cut off the branches.
It's also true that low branches just suck the life out of the top of the tree and suck the oxygen out of the air, that's another good reason to cut them off. It's best to cut the tree down but people sometimes want you to wait until there are ants in it to remove it, so until the ants come, just cut off all the branches.
Trees shouldn't be planted in cities. They only interfer with city life and hurt the grass, basements and sewers.They also cause problems with all that shade, not to mention they get leaves all over. Trees can attract birds and other undesirable animals that poop on my car. Even if the tree is raised to a proper 16 feet, those nasty animals still seem to like them.

Originally posted by Nick Crawford

Yet someone reading this may apply it to spruce and pine trees and to trees that won't conflict with someone's head.

This is a question I have had for a long time. Why is it ok for conifers to have lower branches, but not non-coniferous trees?
This is just silly, conifers need their lower limbs cut off too.
A semi might want to drive across the lawn some day and break off the limbs, like say, when you're moving and they back in the moving van. It's much better to cut off small branches than large ones later. So get out and cut all those branches off!

 

[TheTreeSpyder]

Are we our branches' keepers?

If we are not, then who is; for they cannot be their own.

That is not to say i don't trim'em/cut'em. But in times of grey decision zones, like the public defender i try to do a share of stepping forward to speak for those that can't for themselves well enough to be heard; and argue the defense before the court of decision.

Or something like that
:alien:

 

[NeTree]

I know you're kidding Mike, but you sure do sound like how most people seem to think, eh?

 

[Dan F]

I may get jumped on since I'm a landscaper and not a true "tree guy", but in general, I agree with those statements.

I don't know how tall you are, Guy, but at 6'2", I can attest to how annoying it is to have to duck to walk under a tree along a sidewalk. JPS can probably back me up on that. When I'm working, I usually have on logger boots, so I've got a couple more inches of hieght. Add in my hat, and if any branches touch my hat, they come off at the appropriate spot. By my guess, that gives a clearance somewhere in the neighborhood of 7 feet, which should be enough for 98% of the population to not have to wear eye protection! JP is excluded in this number, of course.

As for trimming street trees, who does that? Usually the trucks take care of that task, they maintain the trees as they drive.

I'll have to dig this thread back out in another two weeks when DadF gets back from the Boundary Waters; a couple of years ago, they were literally following a truck around campus cleaning up limbs.... I'll let him tell the story.

As for trees growing in the lawns, whatever the customer wants, within reason. I won't cut off every limb I can reach with the pole pruners, though it is very annoying to be slapped in the face by limbs when mowing. This day and age it's hard to find any tree that has limbs starting at just above ground level. Most come from the nursery with limbs starting at 5' or so for various reasons. I doubt that will ever change.


Dan

 

[NeTree]

I would say that 7-8 feet is plenty adequate for pedestrian clearance over sidewalks. For vehicle clearance, 14-15 feet would be plenty. Most rigs are 13'6".

 

[Dan F]

Forgot to add that I can understand the 8' clearance on sidewalks. If the pruning is done in the winter or early spring when no leaves are on the trees, the limbs will droop down once they leaf out. With an 8' clearance when pruned, this may allow 6.6-7' of clearance during the season.

Case in point, I pruned some hawthornes about 1 1/2 months ago. They were along a sidewalk, and getting down into where they were a problem for pedestrians, myself included. I pruned them so I could walk underneath them without any problem at the time. Well, last Friday was back at the site, and the trees have since finished flowering and are now fruiting. The added wieght had dropped many of the limbs back down to where they were a problem again. They are now back up to where they are not a problem for me.


Dan

 

[Dadatwins]

Gotta agree with the 16' mark for street side of urban street trees. With rain, snow 16' becomes 12' or lower quickly on some trees quickly. Sidewalk side I would 8' - 10' is ok same reason. Biggest problem with street trees is maintainence cycle for most cities is 5 -7 years or longer between pruning and most times every water sprout, sucker within this range is hacked off in the name of trimming the tree. We all know this leads to more water sprouts , suckers and trend continues. I believe training young trees from start would be helpful but doing on a street tree level is difficult. As for Homeowner trees not that much clearance needed on grass based trees but should still be properly trained from start. Sad part is since I work for the city the hopefully sarcastic views of MM are all the norm that I hear daily from the public. Getting the public and government educated to the benefits of having the trees is the toughest nut to crack. Most times they are planted in street environment as an afterthought and forgoten.

 

[Tom Dunlap]

Measurements and clearances are used to justify pruning for people. That's understandable if we're only serving people. Going back to Guy's original quote there is no consideration for what is good for the tree.

It seems like we're going to go back to one of the routine discussions again. Do we prune to benefit trees or people? To say that, "low branches are seldom appropriate for large growing trees in an urban environment..." shows no regard to what is "appropriate" for trees.

Wulkie opened my mind to the insight that trees need any leaf that they grow. Now...let's not get into structural issues here. The hairs get too thin if we wander over there. Let's keep the thoughts a little more general. What's the problem, if there is enough space, with letting trees have low limbs? If more trees had low limbs more kids [of all ages] could climb them. Would anyone argue with there being anything wrong with having more people climbing trees?

I had to leave a "No-Prune" experiment behind me in Minneapolis. There was an elm in my yard that I planted from a whip. Over the years I could see that the smaller branches that were low on the trunk were dwarfing. Very little twig elongation and the leaves were MUCH smaller than the ones up-top. The top twigs were putting on over three feet of elongation every year. I'm convinced that by having the small twigs on the trunk adding energy and storage volume, more of the growth energy was going to adding top to the tree. When I get around to buying a house here in Denver I'm going to start the experiment all over again. This time I'll take more pictures.

Tom

 

[Dadatwins]

Originally posted by Tom Dunlap
Measurements and clearances are used to justify pruning for people. That's understandable if we're only serving people. Going back to Guy's original quote there is no consideration for what is good for the tree.

It seems like we're going to go back to one of the routine discussions again. Do we prune to benefit trees or people? To say that, "low branches are seldom appropriate for large growing trees in an urban environment..." shows no regard to what is "appropriate" for trees.

Tom

Have to disagree that pruning for clearance on street trees is 'not showing any regard to what is appropiate for tree' If a street tree is planted and left to grow at will and a semi comes by and tears half of it off because the belief of leaving it natural was enforced, what has been proven? Tree is seriously injured or destroyed all because we were trying to serve tree and keep it natural? I think the term 'site appropiate pruning' should be considered when having a discussion about what is better for tree and people.

 

[Tom Dunlap]

Dada,

when we make a decision to prune a tree we only have two choices:

Do humans benefit
Do trees benefit

All other decisions cascade down from those start points.

Trees should be planted along roadways. They also need to be pruned so that the branches don't interfere with traffic. Taking the limbs off for clearance only benefits humans. In no way does this benefit trees.

.If pruning is so good for trees how did they survive for so long without our care? You do realize that arboriculture has really only been practiced for a little over a century. Silviculture style tree pruning hasn't been practiced for much longer. Add to this the fact that its only been since about the mid to late fifties with the use of hand-held chainsaws that we've gotten the idea into our heads that removing limbs is beneficial.

Tom