Before we even get into the details of how to fell a tree, the most important questions we can ask are, “Can we even fell this tree? Do we have room? What are the hazards? (Photo 1) How much lean does it have? Do we have the tools we need?” To determine if we can even fell the tree, we need to create a five-step felling plan. There are probably five or six ways to fell any given tree, depending on several factors. This article will explain a few of the methods and hopefully give you some more options for your felling operations.

Photo 1: Fire-burnt trees are a severe hazard on the West Coast. They can injure wildland firefighters working to put an active fire out, or they become a hazard even after the fire is out. This was right on a road, creating a hazard for those using the area for recreation. Unless otherwise noted, photos and graphics courtesy of Matthew Meckley.

Five-step felling plan
To determine your five-step felling plan, you must complete a job hazard analysis (JHA) with your entire crew. Then you can dig into the plan. (Image 1) You will want to address the hazards, tree height, tree lean, escape routes, the hinge and the back cut. Let’s start with the tree height.

Image 1: The 5-step felling plan includes close assessment of tree height and hazards, the tree lean, planning an escape route, defining the notch and making the back cut. TCIA graphic/Pixabay.

Tree height
You need to figure out where you are going to put that tree when you fell it. Determine the height of the tree and whether the tree is going to fit in the drop zone. If you only look at it and guess that it will fit where you want it to land, you might end up taking out someone’s fence, power lines or whatever you’re working around.

There are a couple of tricks to getting that height, the first one being the Nikon Forestry Pro range finder (or similar device). You look through this device at the base of the tree and then point it to the highest branch tips or the treetop, and the readout will give you an exact height. But that’s a rather expensive device, so here is a quick and dirty, less-costly method – the stick trick: (Image 2)

1. Get a straight stick about 32 inches long.
2. Position yourself along the intended fall line of the tree.
3. Hold the stick in a vertical position with your arm straight, so that the distance from your hand to the tip of the stick is the same as the distance from your eye to your hand.
4. Extend your arm so it’s level with the ground and forms a right angle with your body.
5. Align the base of the stick with the top of where the stump will be, which is typically about one foot above the ground.
6. Use your dominant eye and look past the right side of the stick to the tip of the tree.
7. Adjust your position forward or backward along the fall line until the tree’s tip aligns with the tip of the stick.
8. Measure the distance between yourself and the base of the tree. Where you’re standing should be close to where the tip of the tree will hit the ground.

Identifying and mitigating hazards
Some of the hazards we need to be aware of when felling trees include:

• Hung-up or hanging branches.
• Secondary projectiles (something on the ground or aloft that could get struck by a tree and flung into the work zone).
• Slips, trips and falls from uneven ground, the wrong footwear or a cluttered work site.
• Struck-by, trapped or pinned-by falling branches, etc. Trapped – if you have ever seen videos of someone getting trapped by a log, it doesn’t seem like fun.

Image 2: Stick trick to estimate tree height. Hold a stick vertically at arm’s length so it’s as tall as your arm is long. Walk forward or backward until the top of the stick lines up with the top of the tree and the bottom with the tree’s base. The distance between you and the tree is roughly its height.

The overall health and integrity of the tree needs to be considered as well. Part of your five-step felling plan is to determine if you can even fell the tree. Will it hold up if you need to beat on a wedge and it’s a super-crispy tree? Will it fit in one piece where you want to drop it, or will it explode and fling debris far from the stump?

What are some of the site hazards? If this is a residential backyard, where’s the plumbing? Septic? Where are the power lines? Are there underground wires that tree limbs might possibly stab into through the ground?

Overhead hazards can fall at any time. Continually look up into the remaining canopy for potential falling hazards. This applies to big trees, small trees, dead trees, living trees – hung-up branches have a way of vibrating loose from chain-saw activity, pounding wedges, the wind or random acts of gravity.

Situational awareness is expecting the unexpected. There could be ground bees that will attack from below, so don’t get sucked into laser focus on the task. Stay aware and stay safe.

Believe it or not, your team members could be a hazard! If someone doesn’t know what they are supposed to do or where they are supposed to be, this could create a stressful, if not deadly, work site. All crew members need to understand the work plan and their roles in it. Good communication is a main part in mitigating job-task misunderstandings.

So there are a lot of things you need to consider and make safe before you even decide that it’s alright to follow the five-step plan.

Photo 2: Plumb bob. TCIA staff photo.

Determine the tree lean
Determine the lean or inclination relative to the drop zone/felling direction. Most trees have some sort of lean – back lean, side lean, forward lean. Understanding tree lean will help us with the type of cut we’re going to make and how much leverage we’re going to need. Will we need a pull rope? Will we use a tree jack? Etcetera. We also need to figure out how to mitigate that lean so the tree doesn’t break off if you’re placing a face cut to counter side weight.

Photo 3: Barber chair usually happens while the back cut is being made. Photo by Jim Skiera, International Society of Arboriculture, Bugwood.org.

If a tree is leaning, we need to determine how far the center of mass is away from the felling hinge. Is the trunk leaning left or right, into or away from the line of fall? One trick to help you determine the lean would be to use a plumb bob or throw bag. Stand back and sight the tree like you did using the stick trick. Dangle the bob from the center of mass of the canopy and see if the string aligns with the trunk. If you see the trunk to the left or right of the bob string, then the tree has lean to that side. (Photo 2)

You need to understand the tension in a leaning tree and know when not to cut a tree with too much side lean. We all have climbers on our crew. Send that crew member up there to cancel out that side lean and cut it off so you don’t have a tree go sideways on you.

Consider the branch weight in the total trunk weight. How big are those limbs? How long are they? And how far do they go up the tree? Sometimes, a tree might look like it’s leaning forward, but the limb weight in the top can make that tree go backward. Consider what’s going to weigh more: limbs or wood weight? It really takes a good understanding of where you can find all that weight and where the wood is.

One way to assess how much side weight there is in the canopy is to stand in the fall area and draw an imaginary circle around the canopy with your finger, capturing every branch in the circle. Draw another imaginary line from the middle of the canopy straight down to the base of the tree. The distance between the line and the center of the trunk diameter is how much the tree is leaning to the side. The amount of lean will determine if wedges or rigging methods might be needed.

Make sure to estimate side lean from both sides of the tree. This entire procedure will help us determine the likelihood of barber chairing or whether we need to put a pull rope in.

• Leans can make or break a felling plan.
• Never try to take on anything with a side lean of more than 10% of the tree height.
• Trees with more than 5% front lean have an increased chance of barber chairing. (Photo 3)

Photo 4: A low and level stump with the right amount of hinge. Back the tree jack up with wedges to account for mechanical failure and help release pressure as you get the tree to jack over.

Escape route
This step is paramount. You must plan – and prepare – the safest route out before beginning your cuts. There are too many occurrences of people getting maimed, or worse, when they linger around the stump after the tree begins to fall. You see videos of people staying at the stump with branches and debris raining down on them to look like a hero or to post on social media or something. This is massively dangerous.

Spend some time, five to 10 minutes, to clear everything out of your way. You should practice your escape route. Always!

Sometimes, you might have to set up a secondary escape route as well. You might see something the second time you didn’t see the first, like possibly another snag that could come down in the same drop zone you’re cutting in. You might even need to ask yourself if you can escape safely from there. Is it even feasible to get out of there?

Plan two escape routes and practice them both. Walk them, then run them. Yes, run, because say you try to just walk out and you’re like, “OK, this is all good.” Then it turns out you have to run out your escape route. All of a sudden, your leg spacing is different and rocks and debris are suddenly a hindrance. You do not want to twist an ankle and be caught in the drop zone.

When that tree goes down, get off that stump.

Escape route:

• Rule of thumb is to exit at least 15 feet on a 45-degree angle toward the high side of the tree.
• Use common sense.
• While leaving the stump, keep eyes on the tree and debris coming down.
• Give things time to settle before walking back to the stump – sometimes branches fall several seconds after the tree has landed.

Hinge plan
A good hinge is the most important part of the felling plan. The hinge is the pivot point that holds the tree on the stump and systematically fails as the tree falls. If you have a crappy hinge, anything else you do right won’t matter. That tree’s going to fail. (Photo 4)

Photo 5: Matt Meckley showing the most accurate way to use the gunning sights on a saw. “Directly behind the saw with my strong eye open, picking out a target no closer than 60 feet out. This is how you get the most accurate use out of the sight.”

Establishing the hinge depends on a lot of factors – face opening, depth, position on the trunk, fiber thickness and length, tree species, etc. You need to know what kind of tree you’re working with and what climate zone you are working in. Certain trees will grow at different rates, such as on the West Coast. Trees can grow pretty quickly out there. Oak trees in the Northeast or the Midwest have that winter hardy season when that hinge fiber gets much more rigid with a tight grain. That rigid grain allows the tree to hang on to the stump longer when felling.

Photo 6: Matt Meckley showcasing what a proper Humboldt cut should look like when felling trees. No Dutchman, clean corners and a sufficient undercut for the tree to tip over without barber chair.

The rule of thumb is to make the hinge at about one-third the diameter of the trunk, but that can be situation dependent. All the strength for felling the tree is in the sapwood. So the more we use the sapwood, or outer edges of the tree, the stronger the wood is and the more control we have.

We also refer to the outer edges of the notch as corners. They are the most fibrous and are what holds and controls the tree.

Hinges that are more forward on the stump can offer more control and more surface of the back cut to work with. Hinges toward the middle or rear can help with wedging, but remember to look at what the weight is doing. If misjudged, the tree can sit back quickly, pinch your bar and possibly negate any room for wedges to help control the tree.

Gunning sights
Gunning sights are the lines that are on both sides of the chain-saw housing. They act as a scope or sight, as on a rifle or pistol, to help you line up the direction of fall. Using the gunning sights will help with aiming your corners and creating the back-cut apex for where you want the tree to go. (Photo 5)

To use the gunning sights, put the saw bar directly across the apex of the hinge and look down that gunning site out to the drop zone. You actually have to get behind the saw like a rifle and stand all the way back. Use your dominant eye, just like when hunting, and look out to at least 60 feet into your drop zone. Then flip the saw and go to the other side of the tree and do the same. When you look down that gunning site, make sure they both match up to exactly the same spot in your drop zone.

The saw must be level in order for the gunning sights to line things up properly. If you’re off on your gunning sights (see explanation below) even an inch and you have a 200-foot-tall tree, that can result in being about 10 feet off from your planned drop zone.

Photo 7: Felling or saw dogs help brace the saw for controlled cuts.

Different types of notches
There are different types of notches that allow our hinges to work in different ways, depending on how we want the tree to fall. A narrow face cut allows the hinge to break easily and early, but you lose control of the tree. A wider, open face cut is going to give us the most control of a tree.

The depth of the face cut will depend on the situation.

Conventional notch
The conventional notch is very common and is easily taught. It is used frequently on residential job sites. The conventional notch is defined by the Z133.1 Safety Standard for Tree Care as a directional felling cut into the side of a tree, facing the intended direction of fall and consisting of a horizontal face cut and an angled cut above it, creating a notch of approximately 45 degrees.

Open-face notch
As defined by the Z133.3, the open-face notch is a directional felling cut into the side of a tree facing the intended direction of fall and consisting of two cuts that create a notch greater than 70 degrees. An open-face cut is when you apply that big wide one that’s going to keep the tree on the stump the whole time it falls. A lot of times in a residential setting you don’t even break all the wood fibers, and you can just lay the tree down flat on the client’s turf with a lot of control. If you really need to hit a tight shot, use an open-face notch for the best outcome.

Humboldt notch
This notch is commonly found on West Coast timber-falling job sites. Its purpose is to create more saleable timber by leaving a shorter stump. It also is sometimes used to control the line of fall uphill, to allow the tree to hang up on the stump and not roll downhill. It can be difficult to learn, especially if not frequently used. (Photo 6)

Back cut
The back cut is the fourth part of the five-step felling plan. There are basically two back cuts we use in tree felling – the straight-through cut and the bore cut. Also, before you start your back cut, always make sure you have your axe and wedges with you by the tree. These will help you be more prepared if that tree starts to sit back, or if you need more tools to help commit it to fall.

When starting the back cut, make sure the bar is level. Use your gunning sights again and line up with the direction of fall. Square the cut to the hinge. Dog (see felling dogs explanation below) into the tree and start the cut. Make sure you have responsible throttle control and a sharp chain. Pay attention so as not to cut the hinge corners.

High back cuts cause resistance in the wood. The higher you are, the more resistance you will encounter. This can be good when you need to pull trees, but can cause problems if you’re not. Low back cuts can cause barber chair, which causes splitting. It also will give a lot of resistance and make the tree a pain to wedge.

Felling dogs
Felling dogs make felling operations so much easier. Felling dogs, also called saw dogs or bumper spikes, mount directly onto the chain-saw bar and provide leverage and stability while cutting. Consider putting after-market dogs on your saws, especially if you’re in thick-barked trees. They’ll make your life easier by reducing stress on your body and helping you match up your cuts better. You stick your dogs in and just pivot on the wood. When you pivot on the wood, it’s less wear and tear on your body. Practice pivoting with the dogs on noncritical job sites. (Photo 7)

Make sure the dogs are sharp. Sharp felling dogs stick instead of kicking out when you walk the saw around. They help keep the saw in the tree, which helps take the weight of the saw off of you.

Advanced cut: The Sizwheel
There are several advanced felling cuts to discuss, but for this article, we’ll offer this one.

The sizwheel, sizwall, sizwell or sizzle, depending on where you are in the country or world, is a steering cut that uses a type of Dutchman cut. The idea is to remove hinge wood on the heavy or leaning side, which allows the tree to sit on the stump. Then the other side of the hinge will pull the tree around, following the notch. It utilizes more of the stump-hinge fibers to turn the tree as it falls. Since it uses so much of the stump fibers, it is not uncommon for the tree to pull the entire stump out of the ground as it falls. It is a difficult cut and a little unpredictable, and should not be used in residential settings or settings where there are close targets. (Photo 8)

Photo 8: Three different angles of a siswheel cut. This cut is useful for cutting leaning trees in order to steer them in a particular angle against the lean.

Summary
From basic to complex tree felling, every felling operation begins with an outline of the five-step felling process. Identify and mitigate any hazards that could possibly occur on the job site; determine the tree lean; plan and prepare the safest escape route; consider the hinge location, depth and width; and determine the type of back cut you’ll apply. These five steps are the keys to a successful felling plan.

Ryan Torcicollo, CTSP, is a safety and skills trainer with SavATree, a 39-year TCIA member company headquartered in Bedford Hills, New York. He has about 15 years in the industry and currently resides in New England.

Matthew Meckley is a second-generation arborist, climber and timber faller with his own company, Sure Shot Forestry LLC, based in Grass Valley, California.

This article was adapted from their session on the same topic at TCI EXPO ’23 in St. Louis, Missouri. It was transcribed, excerpted and edited by Tchukki Andersen, BCMA, CTSP, TCIA’s staff arborist.

To view a video recording of that presentation, click here.