PNW "wind thinning" "windsail reduction"

Common residential practices sold are "wind thinning", "wind sail reduction", "wind lacing" or "spiral pruning".

Windsail reduction is often stripping out the inner canopy foliage, aka lion-tailing. Usually this is by climbing up the trunk and cutting what can be reached while "lanyarded-in".
I believe that this is also the same as wind thinning and lacing.


Spiral pruning involved full branch removal in a spiral up the tree.

This allows the air to "blow through the 'sail'" to prevent trees from breaking or uprooting.

Anybody have information that debunks this? I get the idea that there is no data supporting this, and it can be counter-productive and a waste of money.

I suspect that there will be a lot of anecdotal evidence that supports "wind thinning".

You know that topping was once commonly sold.

I was told that (I think it was) Bartlett suggested that topping does actually help with stem breakage and uprooting in the short term. Of course, we know what accompanies topping in the longer term. To be clear, Bartlett was not supporting topping. Just what they observed in short term effects.

What I have heard is that end-weight reduction reduces individual branch breakage, as well as trunk breakage, and uprooting, though it is more difficult, as it requires getting out toward the tips of all the branches.

Anybody have any info to support this, or specifics on the practice, such as how much to reduce branches, and in what parts of the tree, such as upper 1/3, upper 1/2, etc.

We do a lot of it here in KS in Silver Maples close to targets. Have to go back every three to five years, but reduces storm damage to roofs and buildings significantly. Not just what you can reach from a lanyard though, but to keep clean looking branches and a nice stem up to an open canopy.
I call it crown reduction, but most say I have that wrong?

We used to sell wind sail thinning in California and then we were told it was BS but more recently there have been studies done that show it can help if done properly. I am not sure if the study included conifers though. I will find the study and post the link.

Of course topping can reduce the chances of uprooting or breakage short term. But that's applying people time solutions to trees which live on tree time. In five years when the tree topper is long gone, the tree is just recovering from the topping and becomes more likely to break due to the weaker limbs, weaker overall structure and vigor, and decay from the topping cuts.

Lion tailing is crap pruning sold by crap tree hacks who aren't capable of proper reductions or thinning. Climb as high as you can and cut out everything you can reach, whack some good holes in the canopy so the customer knows they are getting their money's worth. The only thing missing is selling the job by the pound for the amount of material you whack out of the poor tree.

Wasn't there a thread posted here a while back called "windfirming" or some such...?

re the windfirming, I hear more people debunking it as I go along. It doesnt change the fulcrum on the trunk, reduces wind that would be deflected around the tree and allows it to pass through the tree possibly increasing drag by increasing surface area exposed to wind, 'furring' out of Doug fir after time to create a trunk with increased drag du to the shoots along its length, general interference of ma nature's aerodynamic deflection and adjustment under wind load etc.

I dunno, if it makes the customer happy and doesnt hurt the tree..... But I would hate to be the defense in a case where a client was told windfirming would make their tree storm proof and try to explain the subsequent failure with possible damage. The main info I heard that I would give credit was Dr Gilman out of U of Florida, at the PNW shindig in Kelowna a couple years ago.

He had a cool set up for blowing the heck out of those trees. His first approach was putting the trees in the back of a truck and driving them down the highway.

Brian, I don't know if you got the wrong impression, if you skimmed what I wrote.

Eric, Gord had a thread about wind-firming. This was very different, as it was for the new edge trees along a logging cut, and want to protect individual trees, but rather the stand as a whole, with some sacrificial/ semi-sacrificial wind-firmed trees on the edges of the cut.

Not topping Brian, eliminating a lot of the smaller branches off the trunk, and growing up and down on the main leaders to open the canopy. Again, this is on Silver Maples which really tend to self prune with our winds. Everything horizontal on the leaders is left, just vertical reduction, and elimination of the 3" or smaller leaders off the trunk.

SouthSoundTree said:

Brian, I don't know if you got the wrong impression, if you skimmed what I wrote.

Eric, Gord had a thread about wind-firming. This was very different, as it was for the new edge trees along a logging cut, and want to protect individual trees, but rather the stand as a whole, with some sacrificial/ semi-sacrificial wind-firmed trees on the edges of the cut.

Click to expand...

Thanks for the clarification.

Sean, I'm not mad at you. I'm mad at the hacks who keep encouraging lousy pruning practices because they aren't capable of doing it right and don't want to do anything any better. They rape trees for money spending the least amount of time possible for the most amount of money. They lie to the clients and perpetuate false beliefs about "opening up the tree so the wind can blow through it" then lion tail the crap out of it, dooming the tree to guaranteed failure within 10 years. I've seen it my entire career and have finally begun refusing work from guys who insist on such hackery. I'd rather cut a tree down than butcher it and leave it to fail one day in the future.

Darin, indeed, he drove them around the track first, then made the ginormous wind generator and blew the heck out of them. Useful for empirical data on small trees but does it translate directly to larger specimens? I would find it difficult to gather data on a 15 foot douglas fir with and without pruning treatment then correlate that to a 100 foot open grown or forest grown individual. I was particularly interested in the aerodynamic adjustment of deciduous tree leaves. Liriodendron, Acer etc, the shape the leaf transformed to under windloading was pretty cool.

What would concern me from the standpoint of validity of data... Is that winds in the real world are rarely sustained and from the same direction. They come in gusts, and can change direction at random. Does the modulus of wood remain linear as size increases?

I'm with you Brian. Usually people spike their way up and down, too.

Its hard to simulate a real windstorm. I think its cool that Gillman is try to test this out though. I think there is a lot of stuff that we do that is still just anecdotal and not scientifically proven.

Erik, with his wind machine he had left and right deflection, somewhat random but I think the wind would still be vertically linear. I would love to see his video again to analyze his methods but it was just the once in a seminar that I had the chance, not sure if its in his downloadable stuff folder at the U of F site.

There may not even be a way to prove it, per se.

I also wonder what the effects are on the harmonics of the tree. Gusts move trees back and forth, and as long as no harmonic is struck... The tree should survive (assuming good structure, etc.) When limbs are removed, would that not change the harmonics of the tree... making it " shake" at a different frequency than before? Would it matter?

I'm not crapping on his work, merely thinking out loud.

Paul, as a pilot I can tell you the wind is never predictable.

I think the video is available on the web.

I base pruning on the sail/crown area, the length of lever, higher the tree the greater the wind force( 80 mph at the ground can be much more at 100'), around or over buildings,structures or trees winds can gain force=venturi effect, it is not the wind pushing that fails a tree so much but the return to rest or natural lay that initiates failure, wood/branch structure(bends, twists, compression, tension wood etc. most big failures I have consulted on occur with wet wood, wet leaves and weird wind.
This last point wet wood was explained to me with the analogy of wet rope. The loss of strength in wet rope is due to the water between the fibres when under extreme pressure will mechanically damage fibre.

Psyhcic Nicky is predicting some unusual storms this years. I hope to get through my 5 years cycle of pruning. I was beggin and discounting work all through January and February with only a few replies.
See what happens.

NeTree said:

There may not even be a way to prove it, per se.

I also wonder what the effects are on the harmonics of the tree. Gusts move trees back and forth, and as long as no harmonic is struck... The tree should survive (assuming good structure, etc.) When limbs are removed, would that not change the harmonics of the tree... making it " shake" at a different frequency than before? Would it matter?

I'm not crapping on his work, merely thinking out loud.

Paul, as a pilot I can tell you the wind is never predictable.

Click to expand...

Harmonics? Thats like a left followed by a right or vice a versa. That is like a tree gets pushed away from its natural lean and as it is returning to rest it gets pushed again and the combined forces snap it.
That makes sense, so the forces are actually compounded mb 5 x, 10x guess it all depends.

Harmonics as in the frequency at which what you describe happens.

Like when the wind set the Tacoma Narrows bridge shaking at just the right frequency to make it rip itself apart.

You got it!

The mass of the tree, limbs included has to have an effect there.

Limbs may add wind drag, but they also dampen the backlash, too.

Darin, you believe so yet you provide no link? You big tease.

Erik. Indeed, I am all for discussing it, shooting holes in an experiment should be taken as professional interest and criticism, defense of theory or methods is welcomed.

I thought wet rope was stronger.

Paul, I just found the machine but not the tree getting blown.

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