Thursday, March 17, 2016

Pruning's Second Priority: Forks, Bad Branch Angles, Included Bark


Strong branch angles are wide, almost 90°.  As branch angles become more acute, they grow weaker.  Forked trees, and forks with included bark are at high risk for breakage, and of course forked trees may not be merchantable as logs, or they will have a shorter merchantable length than unforked trees.


Forked trees are hazardous to property improvements, as is this hackberry that threatens a house.


Pears are all about bad branch angles, and you can't fight them.  Plant your pear trees away from your house so you can enjoy them without worrying when they will break and fall on you.  For pears you can only prune out branches that interfere with one another.  You can't correct their form to what we would like.  We can learn from the damage up close on pears, so study what happens when included bark, weak angles, and wind all come together.


It happens in timber, too, and it is up too high to correct it.  High risk trees like this one should be harvested early, as soon as a harvest occurs after the defective tree reaches a merchantable size.



Maples are always poplular for shade trees, but they are more prone to breaking apart in their joints than any other tree.  This broken tree was ready to fall on a house, and the owner still was looking for a way to save it.  Don't fret over problems like this.  Just take it out before it gets you.


This was a handsome pitch pine with included bark in a high fork.  A strong gust during a thunderstorm whipped it and broke out both sides of the fork.  The dark area at the top is a patch of the offending bark that weakened the tree.


Prevention is the key, if you can reach it.  Cut off one side, first leaving a stub to get the weight off without ripping bark, then make a second cut to get rid of the stub.  Try to do your corrections before the fork passes 2" diameter.  I prefer 1" so I don't have to pull on the saw for long, but a 2" wound will heal quickly enough to keep rot out.

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