TREE SURGERY.

New technique for the styling of thick trunks of pines and conifers.s

By David Benavente

It all started when I was entrusted to work on a pine with an impossible double trunk. Both trunks were extremely thick and out of proportion, and looked in opposite directions. One pointed forwards and the other one backwards.

The problem couldn't be solved with a change of planting position, there didn't seem to be any way to sort it out.

What I really wanted to do was to bend and twist the trunk, and that's when the idea came to me. That was the first rehearsal and it turned out alright, but the technique could be perfected. It was a very drastic intervention but the tree lived without any problems.

I liked the new technique, the result and the possibilities it presented. In order to develop the idea I had to look for the right tree - The one that is shown here.

What is the objective of this technique?

It allows you to twist a thick trunk and to give it the movement which it lacks, or give emphasis to that which it has. It creates a nejikan effect and a shari which (if done right) add value to the specimen.

Development

• Pinus sylvestris.
• March 2003
• Dimensions: 80 x 67
• Trunk diameter: 7 cm

Before the work was carried out. This tree had gone from place to place, probably due to the fact that it showed no signs of ever becoming something. Nobody wanted to buy it, despite the low price, its tiny needles, abundant branching and having been in a pot for many years.

The tree needed a radical change in order to become something and I needed to develop my technique. The perfect match.

Ya está todo pensado, manos a la obra. Lo primero es arrancar la corteza de la zona de trabajo para guardarla. Nos puede servir más adelante y si no para éste, para otro pino de corteza similar.

Sólo hay que eliminar la corteza de una franja vertical muy estrecha..

It's all been thought out, so down to work!. Firstly the bark has to be stripped from the area which is to be worked, and kept. It might come in handy later on, if not for this one then maybe for another pine with similar bark.

It's only necessary to remove the bark from a thin vertical strip.

The tools to be used are important. To carry out this job a powerful router is essential (I use Makita) and a long shafted "ninja" bit to work inside the trunk (www.bonsaispirit.com). I don't like to recommend brands, but I think that this is the only router bit which allows you to carry out this type of job precisely, comfortably and safely.

A channel should be opened up along the length of the trunk which is the width of the router head, and whose length should be determined by the twist desired.

Once this space is opened we can work with the router on the inside of the trunk, cutting away part of the central wood.

As can be seen in the photo, the cut is deep.

The trunk is now ready. Now it's time to bend it. Despite having been hollowed out it puts up a lot of resistance. The clamp allows us to bend the trunk without effort. In the photo the right hand part of the clamp had fallen down a bit. In reality it was placed a few centimetres higher up.

The first twist was done. You can see quite clearly how the trunk has not only been bent, but how it has also twisted around itself.

Next comes the styling of the trunk. Now it's necessary to bend it back in the other direction. This is impossible using wire alone, so we're going to make use of a guy wire. An iron bar is going to be used as a point of support.

So that this second twist can be carried out in exactly the right place, a small stick is used to fix the right point.

March 2003. The front after having worked on the trunk.

Scar tissue has now formed around the cut. Everything is going perfectly.

It's tempting to keep working and to finish the styling process, but that may kill the tree. For the time-being work stops here. The evolution of the tree should be followed closely as the post operation treatment may be the determining factor for the health of the tree.

It should be protected from frosts and intense sunlight and watering should be meticulously controlled. It would be logical to expect the soil to take a long time to dry out after the operation. It should be watered only when it asks for it, that is to say, when the soil dries out. Recuperation will be helped if the crown is kept humid. If the tree shoots correctly it should be gradually reintroduced to the sunlight, until it can be placed in direct sunlight.

March 2004. One year later, the tree was fine. In fact it didn't seem to have suffered at all. I had to take the 'irons' off early but it's kept its shape perfectly.

This year I'd like to transplant it, but I'd also like to style the main branches in order to continue with the shaping of the crown.

March 2004. One year later, the tree was fine. In fact it didn't seem to have suffered at all. I had to take the 'irons' off early but it's kept its shape perfectly.

This year I'd like to transplant it, but I'd also like to style the main branches in order to continue with the shaping of the crown.

March 2005. In its new pot. Repotting was straightforward because the tree has been trained in a pot since 1999.

If you think about it logically, it would have been better to style the crown now and to wait another year to repot, this would allow us to choose the pot depending on the design of the tree, but it wasn't done this way as the repot couldn't wait.

The health of the tree should always be the first priority.

As time has passed the curves of the trunk have become smoother, so it's become necessary to redefine them. This time the clamp won't be needed, but we will need the iron bar, guy lines and the stick. The process is exactly the same as before.

Now the first curve of the central section is what we wanted, but the apex has become very vertical.

A guy line fixed to the iron bar is used to move the apex to the right.

We've superimposed the first and last photos (before and after) so that the change in the trunk can be studied.

December 2005. Work finished. 70 x 52.

< back