tree moved in windstorm

Discussion in 'Woody Plants' started by summerlily, Dec 17, 2006.

  1. summerlily

    summerlily Member

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    Time running out for this old walnut tree!

    I have a beautiful, 40 year old walnut tree that has moved in the ground during one of our recent windstorms here in the lower mainland. I need advice and information about what to do. Can it be saved, or does it need to come down before it falls into our neighbours yard next snowfall, hard wind, etc...
    I was thinking some heavy pruning??? The property is on quite a slope and the tree has shifted ever so slightly more to the south. It has more growth on the side facing the south and this combined with the slope is probably the real problem. I have added some pics, (sorry about the fuzzy quality), to show the size and growth. Hope this description is helpful.

    Please help me save this tree, any info will be gratefully appreciated.
     

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    Last edited: Dec 17, 2006
  2. Rima

    Rima Active Member

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    Don't prune it now - bad timing, but if you can get some help (a tree doctor or even just some friends?) you may be able to get a very strong cable around it (~2/3 of the way up) and secure it on the topside for a year til it's re-established itself. You could prune in spring, but remember, unless you remove branches altogether, where you cut can result in more branching, rather than less (maybe do some on the topside, while possibly removing 1-2 major branches on the downside).
     
  3. jimmyq

    jimmyq Well-Known Member 10 Years

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    you could consider using a ground stabilizing system, there is a product that uses duckbill anchors and wire rope, install it for a year, loosen it and leave on for another year or so and let the root system grow back to replace fractured roots.
    In the first picture it looks like a new house in the background, is this a new development? If so has the growing environment changed for the Walnut? drainage patterns, wind exposure, sun exposure?

    Pruning to thin the heavier side is not a bad idea but dont take too much off.
     
  4. summerlily

    summerlily Member

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    The new house in the background is actually the lot next door, across a driveway from our property. Nothing has changed in our yard accept for the wall to the left of the tree which was built about 5 years ago, (and no soil was moved away from where the tree roots are).
     
  5. Ron B

    Ron B Paragon of Plants 10 Years

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    It seems to me if roots cut/torn to put in wall etc. that could perfectly well be why the tree is leaning towards them. The new(?) bed looks quite close. If you can't secure the top in place you'll have to cut the tree down, or risk it toppling suddenly onto whatever (or whomever) is in its path.
     
  6. summerlily

    summerlily Member

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    Thanks for your help and information. I really want to try and save it and as it is probably 40 or 50 ft high I guess I have some calling around to do. I definitely don't want it to topple over on anyone/thing!
    Happy Holidays!
     
  7. M. D. Vaden

    M. D. Vaden Active Member 10 Years

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    I was thinking the same thing.

    Often, there is no better time to prune a tree, than when it needs it, like to alter the balance of wieght a bit after a lean. Let alone that this is a nice season for pruning.

    Light pruning would be my option too. Possible the removal of the lower right limb in the photo, and possible length reduction of a few limbs on the upper right, although it's hard to tell without looking.

    You may need to aerate that lawn and soil if it drains enough so that it's not mushy.

    Heavy pruning may be among the worst choices.
     
  8. jimmyq

    jimmyq Well-Known Member 10 Years

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    well here comes some more wind, keep clear of those questionable trees tonight....
     
  9. jamkh

    jamkh Active Member

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    If you want to improve stability of a plant, its height is the prime consideration. With its present height you would have a tough job to maintain stability. Why not lop off the top sufficiently so that even if it topples it does not reach your neighbor's nearest housewall. I am guessing the fence can easily be repaired at a reasonable cost.
     
  10. Ron B

    Ron B Paragon of Plants 10 Years

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    Well, because then they will have a topped specimen. Depending on how much topping was done, not much better than a toppled specimen, either way the tree has been wrecked. Mature trees especially really do not appreciate being topped.
     
  11. jimmyq

    jimmyq Well-Known Member 10 Years

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    " lop off the top" of a 40 year old walnut tree? thats a little silly. If that is something you would consider then remove the tree entirely. If you did want to manage the height of the tree you could have the crown reduced without lopping, or topping the tree indiscriminately which will cause more problems than it will solve.
    http://www.plantamnesty.com/stoptopping/5reasonstostoptopping.htm
    http://www.treesaregood.com/treecare/topping.aspx
    http://dnr.state.il.us/conservation/forestry/Urban/Treetopping.htm
    http://www.aginfo.psu.edu/PSP/01psp/pr/01141_pr.html
     
  12. jimmyq

    jimmyq Well-Known Member 10 Years

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    I disagree with this statement also. This tree is not a tall narrow specimen, the overall size of the canopy is what determines wind load and therefore pressures on the tree and the tree's roots. Recent discussion and opinion is that thinning trees or other attempts to reduce windsail are not necessarily effective in reducing wind loading damage.
     
    Last edited by a moderator: Jan 2, 2007
  13. Ron B

    Ron B Paragon of Plants 10 Years

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    Yes, you have to wonder how removing a small percentage of a large object is going to keep one that was going to blow over from blowing over. Reducing a tree enough to significantly cut its wind resistance without reducing it enough to throw its life processes out of whack is probably seldom, if ever possible. Trees have an energy budget, if cut away or kill enough of a tree it goes into a decline from which it doesn't recover. The whole is an integrated system, reducing the whole can shut the system down.
     
  14. jamkh

    jamkh Active Member

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  15. Ron B

    Ron B Paragon of Plants 10 Years

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    It's more than aesthetics. If you understand what topping does to trees, you do not recommend it.
     
  16. jimmyq

    jimmyq Well-Known Member 10 Years

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    disagreeing like gentlemen is quite acceptable. No need for flaming here merely rooting through information to enable proper digestion and offer possible solutions.

    In regards to the physics, I have a bit of a different take on it. to me the center of gravity is immaterial in wind loading when concerned about trunk fracture. The important part is how the tree flexes, I think the pivot point is referred to as the fulcrum when disussing levers. the foliage pattern can be very influential in regards to the fulcrum. a tall tree with branches and leaves down to the ground will have its load spread throughout the branched canopy with the fulcrum being at or near the lowest point which would be the thickest part of the lever, the basal trunk; hopefully but not always (due to possible decay) the strongest part. However if a tree is pruned with a raised skirt or at worst lions tailed, then the fulcrum point is much higher on the trunk and quite likely at a muche weaker point on the lever arm.

    That said, if we are talking soil failure (hinge failure or rotational) then the taller the specimen, the more force it would impart on the attachment point of the lever, it's base. That is assuming all other factors are equal.

    so maybe we can both be right? :)
     
  17. jamkh

    jamkh Active Member

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    Your lever configuration is correct if you refer to trunk fracture. You have created a rather complex lever where the fulcrum is indeterminate and would puzzle more minds.
    Mine is the simple lever and is applicable only when the tree topples by being uprooted.
    In this case we can both be correct and be most agreeable too.
     
    Last edited: Jan 3, 2007
  18. jamkh

    jamkh Active Member

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    Ron
    You are correct and I definately won't recommend it to myself. But it's her tree and her risk at the same time. So she alone is priviledged to make her own decision and bear the consequence if disaster strikes.
    With the weight off my chest, I would caution all people who have huge giant trees close to home to be conscious that the anchorage of these trees will always be suspect especially when we are expecting more ferocious storms in the future due to global warming. Prudence here is the better part of valor, I guess.
     
    Last edited: Jan 3, 2007
  19. Ron B

    Ron B Paragon of Plants 10 Years

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    Trees are individuals, each one in varying condition. To assess risk near structures each tree needs to be examined individually. Lots of treed properties escape serious incident for indefinite periods, it does not automatically follow that if you have trees around you there will be a mishap while you are present on the site. However, all trees do age, decline and topple at some point.
     
  20. summerlily

    summerlily Member

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    Wow!
    I'm not sure I got all that but thank you all for your contributions. It wouldn't be the first time we cut down a tree in this yard, (or had one fall over in a wind storm for that matter). The house and alot of the trees and bushes are over 40 years old so things have had to be moved and/or taken out periodically during our time here.
    I will post our progress,
    Thanks again!
     
  21. Ron B

    Ron B Paragon of Plants 10 Years

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    Not very old for most kinds, actually.
     
  22. jamkh

    jamkh Active Member

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    Summerlily,
    Looking at the picture of the tree closely, I notice that the ground is sloping in tne direction of the lean (i.e. in the direction of the wind as well). Now let us apply the action of forces on a tree growing in soil with a slope of say 'z' degs from the horizontal. When a tree topples, the active force exerted by the weight of the tree acting in the direction of the lean is w.sine ('z'+'l') where w is the total weight of the tree ( trunk, branches, foliage and root mass) and 'l' the angle of the trunk from the vertical. When the angle of lean increases this force also increases (following the sine curve).
    What is interesting is when the lean is in the direction of the slope, the center of gravity of the tree starts to drop lower. Thus this inbuilt force is added to the wind load as the tree topples in the direction of the lower slope. However when the lean goes in the direction of the upper slope its center of gravity rises until the lean angle is 'z' degs. Thus the inbuilt force acts against the windload and the resultant force is [windload minus w.sine 'l'] (meaning the windload has to lift the tree load against gravity in order to topple against the line of slope). Thus we find in most cases the tree topples towards the lower slope.
    Therefore if you're planting a tree on a slope, for better stability you must train the trunk to lean uphill growing at an angle equal or greater than the angle 'z' for a couple of feet before allowing it to grow upright. It may look funny, to some it may be a kind of bonsai (very basic form). But this measure will surely guarantee you a better anchorage for your tree.
    Another important point to note is never grow any big tree if the prevailing wind is lined up in the direction of your down slope especially when your house is situated in that direction. So please check your own situation before disaster strikes.
     
    Last edited: Jan 12, 2007
  23. jamkh

    jamkh Active Member

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    The above statement applies to certain families of trees only. From what I had observed in my neighborhood, many large old trees have been topped by more than 2/3s its height and they rejuvenated very well. Examples of these trees are London plane tree, willow, flowering cherry, magnolia, cornus and many other genera. Yesterday on our hike along the dykes in the Boundary Bay area, we came across this particular tree which had been loped completely at a height of maybe 10 feet from the ground without any apparent distress.
    The photo is taken by Mr Peter Vengshoel.
     

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    Last edited: Jan 10, 2007
  24. Ron B

    Ron B Paragon of Plants 10 Years

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    Operative term apparent. Apparently you need to look more closely, for decay, weak crotches, cluttered and crossing branches. That a tree grew a forest of new trunks after topping doesn't prove it didn't have its energy reserves run critically low as a result.

    Platanus are favorites for pollarding, they will put up with it for a long time. Willows can be and often are stooled, in fact some kinds are more attractive and satisfactory as garden ornaments managed in this way than "let go." No surprises there. But severely topped flowering cherries, magnolias or *shudder* dogwoods being "very well" afterwards? I don't think so.
     
  25. jamkh

    jamkh Active Member

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    I presume most of the home owners had decided to scale down the heights of their trees for the sake of safety. Of course the trees looked awful unless you want to develop the broom shape. However like the 'choped trunk technique' employed in bonsai to achieve a powerful thick tapered trunk these trees can be trained to be quite presentable and without the risk of toppling. They believe this is the lesser of the two evils.
     

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