Notching to Lean...
By Tim Ard, Forest Applications Training, Inc.

So many people think the notch determines the direction and lean of the tree when falling / cutting a standing tree. I constantly hear statements to the effect that if you make a notch deeper into the tree you will be able to make the tree go or lean in the direction you want it.

I think a lot of that thought process comes from the days of logging the big trees. If you have a tree that leans back five feet and you cut the face notch in to a depth of six feet then the tree will go in the notched direction. The farther you cut the notch in, the easier it is to tilt the tree in the desired direction. In that case, if it worked, the tree was probably fifteen feet in diameter. If you take a four foot tree that leans back three feet and you cut in four feet - you will have a tree going the wrong direction. You just cut it off the stump. If you notch in farther than the weighted center of the tree, and don't leave enough material to support the tree's weight, then the tree will unmistakably fall wrong in the weighted direction. It can be confusing... I agree.

Let's go back to the plan and basics to see what really happens. The lean of the tree is not formed as much from the trunk's angle as it is from the total shape of the crown or the tree canopy. To begin to check lean you must place yourself in the position, or in line looking into the position you wish the tree to end up on the ground. Now start the process to measure the side lean. Standing at the exact place you want the tree, take a look at the farthest limbs of the tree canopy to the right, now to the farthest left. Take note of a visual point in the middle of that measurement or the center between the two points. Now draw a plumb line down from that center of the canopy to the base of the tree- at or near its stump. If the plumb line falls to the right of the trunk center, the tree leans right- if to the left of center, it leans left. It's simple but a very important calculation. Now for the second lean...

Parallel to the hinge, ninety degrees to the lay or target, take the lean info as before with the side lean. Point to the farthest left and right sides of the canopy (checking forward to or back from the target). Note the center of the two and plumb the line to the base of the tree. If the plumb line falls in front of the hinge the tree leans forward, if behind the hinge, it leans back.

The back lean or forward lean of the tree must be determined from a position ninety degrees to the target or lay position you want the tree to reside when down. The hinge material just behind the notch will hold during the fall like a door hinge. Consider the hinge as the pivot or fulcrum. The hinge is the balance point of the tree. This hinge is the determining factor in weight position regarding back or forward lean.

If the weight line falls behind the hinge, the tree will not fall in the notched direction on its own. You will need to use a wedge, rope or some other mechanical advantage to move the weight center forward of the hinge to place the tree in the desired direction. It may mean that your plan requires taking the tree down from the top or removing crown weight in some fashion.

Trying to swing or pivot a tree on the stump is not a reliable technique in any situation, especially not in select cut forests where canopies may intertwine or residential areas with obstacles close by. Removing the hinge to pivot the tree is very dangerous as it places the operator in a more risky position as the tree moves. Limbs or debris may fall in the work area causing struck by injuries or fatalities. When a tree begins to move you should immediately seek your planned escape position 45 degrees away from the fall direction and as far from the stump as possible.

Wind conditions, vines, intertwined or grown together limbs can all effect a trees fall. They don't change the weight and lean but they do offer resistance to the fall and can cause unpredictable falling hazards. We suggest you enroll in a hands on instruction workshop to better understand leans and control of the tree if this is confusing to you. It is difficult to explain in words, it is much more absorbable in picture or hands on demo form. Workshops are available - contact Visit our website at for other information.

(c) Copyright 2010 Forest Applications Training, Inc.