Shade tree crown reduction? root stimulator?

[shad]

Hurricane Ike came through a few months ago and blew down a lot of big shade trees here in northeast Texas. I have several in my yard that made it through the storm, but I want to know what I can do to try to make sure they don't blow down next time. I thought about attaching guide wires to them, but that would sure be ugly, and I couldn't think of a good enough anchor. Now I'm thinking of maybe reducing the crown of the trees so the wind can blow through the tree rather than toppling it. At the same time, I thought it would be really great if I could use some type of fertilizer to strengthen the root system. Any comments or suggestions would be greatly appreciated.

 

[Ed Roland]

Check out what Dr. Edward F. Gilman, University of Florida has to say about the subject of reducing the canopy to better withstand high wind events.

Resist conventional fertilizing but consider a nice fat mulch ring all the way to the drip line. Good luck.

 

[shad]

Thanks for the great link on pruning.
What manual pole saw would you recommend? Also what make and model hand saw would work best?
Thanks

 

[treeseer]

What manual pole saw would you recommend? Also what make and model hand saw would work best?

The tools that work the best are the ones in the hands of trained professionals.

 

[Ed Roland]

Shad, cutting material off your tree is bad news. ANSI A300 pruning standards allow up to 25% of live foliage removal on mature trees. A ridiculously high percentage, i reckon, to generalize the many specie with skill level of arborist. Removing live tissue on a mature tree forces it to react and expend energy unnecessarily causing several potential problems. Think of each leaf as a small food factory for the tree. Refrain from removing any live foliage from a stressed tree because they need as much sugar-generating capacity as possible. Weaken the top and you weaken the bottom.
Instead concentrate on optimum cultural practices. If you feel you must exert energy and money then consider inoculating the soil with mycorrhiza. A fungus that could help your tree perform processes.

I'm not sure northeast Texas qualifies for the energy and expenditure it would take to practice Dr. Gilmans techniques but it would require an experience arborist to pull it off without doing more harm than good.

 

[shad]

Well I guess one way to look at it is my shade trees made it thru Hurricane Ike when allot of trees in this area didn't, so that may mean my trees are a safe bet to make thru next time. They've been stress tested and passed.
Shad

 

[Boa07]

Shad, cutting material off your tree is bad news. ANSI A300 pruning standards allow up to 25% of live foliage removal on mature trees. A ridiculously high percentage, i reckon, to generalize the many specie with skill level of arborist. Removing live tissue on a mature tree forces it to react and expend energy unnecessarily causing several potential problems. Think of each leaf as a small food factory for the tree. Refrain from removing any live foliage from a stressed tree because they need as much sugar-generating capacity as possible. Weaken the top and you weaken the bottom.
Instead concentrate on optimum cultural practices. If you feel you must exert energy and money then consider inoculating the soil with mycorrhiza. A fungus that could help your tree perform processes.

Excellent post woodweasel

 

[Ekka]

Any comments or suggestions would be greatly appreciated.

I would recommend you take a soil core sample and see what soil layering and profiles you have there. Be careful and avoid tree roots.

For example, do you have a sandy/loam over shale rock? Layering like that means soil profiles can tear away easier especially when wet and loaded by wind force acting against tree roots.

Once you know the layers and profile then there's a few things you can do.

We know that most uprootings of healthy trees occur when ....

* Soil is soaked
* Extreme wind
* Large canopy in leaf (as a bare tree has less sail)

And we also know that most uprootings occur within 2.5m of the trunk, that's the danger zone.

So, knowing what the drainage is like is another aspect you can work on to reduce the soils likelihood of getting bogged.

Where anchorage is required and the subsoil is shale etc boring holes which then get filled with sand or even polystyrene creates fissures the trees roots can exploit, try not to glaze the sides of these holes or roughen them up afterwards with a steel rod etc.

A study of uprooted trees in SE Queensland revealed some facts that throw away contemporary thinking.

Source (not ISA ): http://eco.confex.com/eco/2007/techprogram/P5725.HTM

Upright trees in our study site did not tend to have their longer and taller buttresses oriented towards the direction of annual prevailing winds, a finding contrary to some other studies. Uprooted trees lacked buttress length on the side opposite direction of fall, supporting the tension member hypothesis, which predicts that buttresses prevent trees from uprooting when subjected to asymmetric loads due to external forces, such as wind. Of the indices of buttress strength, the longest buttress of each tree was the best indicator for direction and magnitude of overall buttress support.

Work with anchorage and soil, of course Woodweasel's recommendations for inoculating the soil with mycorrhiza should also be done, however do work the side of the tree opposite to the prevailing winds.

I've heard of work done where large stainless steel rods were anchored into bedrock that were like a U-Bolt over tree roots. Roots like branches will "swallow" the rods eventually.

Engineers are also placing large trees on roof top gardens, there's a bollard system on top of the building and soil above that, the tree roots intertwine in those bollards to be anchored.

In the attached picture what you can see is a 25cm thick sandy topsoil upon a hard clay base. The tree roots will spread and not want to penetrate that clay base. Now conventional thinking would say, great, spreading root system. However, this is where layering can be a problem and soil separation occurs.

So without knowing what your soil profile and layers are you could be wasting your energy expanding the lateral root surface instead of giving the profiles some clamping capacity. Remember, the vast majority of up rootings occur within 2.5m of the trunk.

 

[Ed Roland]

So without knowing what your soil profile and layers are you could be wasting your energy expanding the lateral root surface instead of giving the profiles some clamping capacity. Remember, the vast majority of up rootings occur within 2.5m of the trunk.

Really good point on the crux of the matter. Ekka rarely disappoints!

 

[shad]

Wow, I never thought of soil layer seperation as a cause for blow over but that makes so much sense.
I happen to know my soil layers pretty well because I tryed to drill my own water well. I went down about 41 feet before I gave up on the well.
I have about 4 inches of topsoil, then 6 inches of gravel mixed with clay, then about 9 feet of pure red clay that turns to white clay. At about 10 feet is a thin layer of white sand. It continues being thick layers of clay and thin layers of sand all the way down to 41 feet. I didn`t find any bedrock. Just lots of heavy clay.
Any thoughts on anchoring my layers together or my roots down? Thanks,
Shad

 

[Ekka]

I have about 4 inches of topsoil, then 6 inches of gravel mixed with clay, then about 9 feet of pure red clay that turns to white clay. At about 10 feet is a thin layer of white sand. It continues being thick layers of clay and thin layers of sand all the way down to 41 feet. I didn`t find any bedrock. Just lots of heavy clay.

If you want to get real creative and KNOW what layers your tree roots are "chillin' in" then perhaps do a small core test. My gut feeling says that the top 4" have maybe 75% of the trees roots, the next 6" maybe 20% and under that 5% if you are lucky. I'd say separation would occur at the 10" mark where the gravely clay meets the pure red clay.

I have used thin walled pipes, screwed them (and hammered) into the ground (serrate the bottom edge lightly with angle grinder like mini saw teeth) then got an angle grinder to split them open. I'd suggest taking 1' at a time as sometimes the soil stops "tubing" into the pipe and all you do is compact the bottom of the hole you are boring.

Now what you look for is root density at the various horizons. You will then know ...

1/ what the depth of roots are
2/ what root density you have at those depths
3/ what soil horizons you have

Tree roots will exploit sandy areas a lot easier than clay. If you can unite the sandy areas that would be the shot.

How you do it?

Long auger bit on a drill (there's extension pieces you can attach), only has to be 1" dia, maybe a hole every 2' square ... get no closer than 5' of the trunk and avoid hitting large structural roots. Once you have augered the hole pour in coarse sand or fine gravel (washed as in cleaned, no fines!). This is where polystyrene is handy as sand or gravel mixed with clay can make cement, so there are applicators that blast those small bean bag balls down there.

Tree roots need air, water and nutrient. Biggest problem at depth is air, water and nutrient will leach down those holes.

Here's a pic of one I recently did comparing 2 properties.

 

[OLD CHIPMONK]

Eric; "thanks for sharing the knowledge & your good posts" !

 

[shad]

Thanks again Ekka, great info. How deep should I make the 1" holes? What diameter should I make the 2 foot grid? All the way to the drip line or would it go by the tree trunk diameter?
So you are saying that the tree's roots will use these holes to expand downward thereby anchoring the tree? About how long will it take for the roots to do this? Will this procedure need to be repeated in the future?
I was thinking I would need to drive down some anchors with tentioned cables
to tie the soil layers together but your idea is much simpler.
Shad

 

[Ekka]

To simplify answering I'll write in red within your post.

Thanks again Ekka, great info. How deep should I make the 1" holes?

The deeper the better, to the next sand horizon would be good.

What diameter should I make the 2 foot grid?

With the 1.5m away from the trunk being the starting zone I'd suggest you work outward to the just past the drip line, that's the "soak" area.

All the way to the drip line or would it go by the tree trunk diameter?

Hmmm, answered this above.

So you are saying that the tree's roots will use these holes to expand downward thereby anchoring the tree?

Yes, while you can deploy mechanical anchors (a known engineering feat) the tree roots will grow down these. They'll put out finer roots to the sides .... imagine a toilet brush down a pipe.

About how long will it take for the roots to do this?

Depending on weather and the trees vigour I'd say a year or two.

Will this procedure need to be repeated in the future?

Yes, and try not to re-drill the same holes, repeat every 2 years.

I was thinking I would need to drive down some anchors with tentioned cables
to tie the soil layers together but your idea is much simpler.
Shad

Tree roots will do the work, at the end of the day it's up to them to create enough friction to prevent soil shear. This is a "natural" plan. Do not put fertilizer or anything else down them holes, let nature do it's work. This will also aid in drainage, part of the reason trees blow over is water tends to accumilate at horizons which reduces soil friction. On sandy islands like say Fraser or Moreton here it's no problem for tree roots to go 20'+ to tap into the water table, air is the secret ingredient. Maybe the only thing I'd suggest go down those holes is some mycorrhiza fungi, let nature do it's work.

 

[shad]

Thanks Ekka. What a great solution. I can keep my shade trees and have piece of mind that they will be properly anchored.
Shad

 

[Ekka]

Thanks Ekka. What a great solution. I can keep my shade trees and have piece of mind that they will be properly anchored.
Shad

And drained, remember that dry clay is strong, wet clay ... well ask the lady wrestlers! LOL

 

[treeseer]

Trees naturally form sinker roots where the soil allows. Drilling deep holes makes channels for sinker roots to follow. Yes air is the limiting factor. Makes a lot of sense to work with the bottom half of the tree first. Sometimes the top half does not need much work at all.

 

[TreeTopKid]

I went out to about thirty ( or more actually) customers prior to hurricane Ike who wanted me to remove part or all of their trees. There was 'tree hysteria' going on because Houston was pretty close to the action. Some people with less scruples cashed in on this. In all except one case the trees posed no threat to themselves or their property I advised the customers to deal with their trees after the storm. If their was any damage to their trees I would be more than happy to help them.

After the dust had settled only one person called me back with regards to Weeping Willow that I had advised may blow over as it was a little top heavy due to a 'home prune' and had suffered a remarkable amount of Sapsucker activity. So we cleaned up the tree for her.

Unless a tree poses a significant threat to human safety I think anyone is ill advised to do anything to their trees prior to a storm as the losses suffered by the storm are great enough. to support this statement further. On a college campus where I maintain the trees a lot of the losses were unexpected prime specimens, whereas a lot of the trees that were more likely to fail by design such as co-dominant stems, or decaying examples actually survived. it is almost impossible to tell what trees are going to fail in a storm with the exception of the screamingly obvious. So save yourself some money. 'If it ain't broke don't fix it'.

 

[Boa07]

Now first off let me be clear I am not having a go at anyone who has poste the advice seems to be very well considered and imaginative....however i would whole heartedly agree with TreeTopKid, it is absolutely true that we have no way of knowing with certainty just how the wind loading during any storm event will be distributed across the landscape or even through a single property.

If wee have an imaginary model of wind loading as a constant in a storm or akin to a wave during a storm on the ocean, we are way off the mark...all the studies done that have attempted to evaluate the behaviour and dynamics of wind loading during storms have taught us that wind turbulance and vorticies are far more accurate descriptors and trying to predict how they will emerge and enact on trees well...good luck with that!

As TreeTopKid said so long as your tree does not have glaring defects within its structure and is healthy best leave the chainsaw alone....making the roots healthier is always a good plan whether you are in a recognised storm zone or not.

 

[Ekka]

As TreeTopKid said so long as your tree does not have glaring defects within its structure and is healthy best leave the chainsaw alone....making the roots healthier is always a good plan whether you are in a recognised storm zone or not.

The forgotten part, sadly. :deadhorse: (out of sight and out of mind to many)