How to prune a tree

There are 2 basic concepts that you need to learn before diving in. Once you learn them, then we can look at the different styles of tree pruning and shaping.

They are the collar cut and the step cut.

This technique is one of the first things an arborist learns when they go to TAFE.

What it the collar? It refers to the branch tissue marked with a bark ridge that connects to the tree trunk.

Why is it important? When pruning a tree and cutting through or removing the collar can hinder the structural integrity of the tree. This is because when we make a cut, it opens up a wound on the tree that needs to heal. Just like with humans, the bigger the cut, the greater the chance of infection and the longer it takes to heal properly.

By making a cut along the collar seam, you are taking the shortest line between two points and reducing the wound you are creating.

While it heals, insects, water and rot can set in compromising the structural integrity of the tree. Leaving a buffer zone allows the tree time to heal without causing any major issues with the trees architecture.

Below is an illustration of the right and wrong way to identify the collar and make the cut.

Before you make a collar cut, do you need a step cut? It depends!

When pruning larger branches, which basically includes anything you need a saw to get through because your secateurs are not strong enough you will need to perform a step cut first before cutting along the collar ridge.

If you were to just go straight for the collar cut, when half way through the cut, you run the risk of the branches weight snapping the remainder of the branch.

Why is this bad?

Because it usually tare’s away a big ugly part of bark with it.

First step cut (A,B), then a collar cut (C)

The small cut A is there to stop the bark taring. It is made only 1/3 (or less) of the way into the branch. Any more than that and the weight of the branch can trap your saw in.

Below is an example of a cut made without a stop cut. Notice the huge wound opened up.

This is not simply the removal of a few random branches back to the trunk. It is actually the selective pruning of 3rd and 4th order branches to reduce the overall size of the tree. Think of it like giving the tree an even hair cut all over.

This is probably one of the more expensive tree pruning jobs you can have done as it requires the climber to go out to every extremity of the tree and remove small branches.

It is time consuming, but well worth the effort.

Just as the name suggests, crown thinning is the process of selectively pruning branches with the trees canopy to make it less dense.

The main reason for this is to let more sunlight through for grass to grow or for more natural light to enter a homes’ windows.

On larger trees this can literally be a life saver. By removing dead and decaying branches you remove the risk of one of them breaking off and becoming a hazard to anyone under the tree at the time.

Even very small branches no thicker than 2cm can build up speed very quickly and will smash roof tiles and anything else in their path.

It will also make a huge difference to the look of the tree. The biggest changes can be see on trees like the Eucaluptus nicholii and Silky Oaks.

This is a very common and inexpensive tree service. It involves the removal of several of the trees lower branches so the main canopy of the tree is higher off the ground. The cost of a canopy lift varies from tree to tree, but you can expect to pay anywhere from $200 – $800

It is a very straight forward job, but can make a huge difference to the look of your tree and garden.