Air-Layering A River Red
Posted: January 25th, 2009, 9:50 am
Gday folks!
Please find attached some pics of me attempting to perform an air-layer on a River Red Gum (E. camaldulensis).
This tree is a product of air-layering itself, and is the 'offspring' of this little Euc. In keeping with my belief that it is of utmost importance to create trunk movement early in the life of a Euc, I wired this one to within an inch of its life about a year ago. Turns out I was a little too vigorous, and I have paid the price by creating a nasty bulge where the trunk had snapped during the bending process. I could have simply chopped the trunk below the bulge, but the movement I had achieved in the upper trunk was too nice to throw onto the compost heap. Besides which, I know from experience that this specimen is well-suited to potted culture and the layering process, so the upper portion of the tree deserves at least a chance at becoming Bonsai stock.
In order to better turn the bulge into an asset rather than a liability, there are two things I will do here: [1] Ensure that the layer site is located at precisely the widest point on the bulge; and [2] Use a method known as a 'skirt layer' (more info here). So here goes...
Using an appropriate tool for the job (in this case, a cheap paint scraper with a new 'Stanley knife' blade inserted), a single cut is made around the entire trunk at the widest point of the bulge. (Rather than slicing the bark, it is preferable to press the knife edge straight into the bark and rocking it from side to side. In many cases, there is a noticeable 'pop' when the blade has penetrated the bark to sufficient depth.) Another cut is made about 15-20mm below this, and the two cuts are joined by a vertical cut. (A standard rule of thumb when layering is that the width of the ring of bark to be removed should be 1.5 times the diameter of the trunk at the layer point.) The resultant ring of bark is then removed from the trunk - if the cuts have been made correctly, the ring will pop off with no need for cleaning up the wound.
Here is where the 'skirt' method differs from standard air-layering: above the site where the bark has been removed, a number of vertical cuts are made so that the bark may be lifted (like the pleats on a skirt). In this case, I recall 7 or 8 cuts were made, each about 5-6mm apart.
Traditionally, the lifted 'skirt' is held in place by means of a ring of wire which is pushed up and under the flaps. Far be it from me to be stifled by tradition, I have come up with a much easier and safer way to get the 'pleats' to lift and stay in place: the humble tiler's wedge! They are so sharp at the point that they are easily inserted under each individual pleat, and their taper allows the pleats to be gently lifted to the desired point.
Initially, I had intended to wedge every second flap in order to create a more undulating root flare, but decided that a Euc like this could use all the help it could get in trying to achieve a nice Nebari. In the end, I wedged every flap except the one where the original wiring injury had occurred, as the bark there had grown into the broken heartwood, making it impossible to safely lift the flap (refer to the 3rd and 9th pics). Using 3 heavy duty garden ties fed into each other around the trunk, I created a platform which would help support the layering pot.
The split pot was then carefully placed around the trunk, duct taped back together, and gently filled with a 50:50 mix of chopped sphagnum and my standard Native Bonsai mix, so as no to disturb the wedging.
Now all I can do is water and wait. (Hopefully the layer takes, or else I'm gonna look like an idiot...)
Thanks.
Fly.
Please find attached some pics of me attempting to perform an air-layer on a River Red Gum (E. camaldulensis).
This tree is a product of air-layering itself, and is the 'offspring' of this little Euc. In keeping with my belief that it is of utmost importance to create trunk movement early in the life of a Euc, I wired this one to within an inch of its life about a year ago. Turns out I was a little too vigorous, and I have paid the price by creating a nasty bulge where the trunk had snapped during the bending process. I could have simply chopped the trunk below the bulge, but the movement I had achieved in the upper trunk was too nice to throw onto the compost heap. Besides which, I know from experience that this specimen is well-suited to potted culture and the layering process, so the upper portion of the tree deserves at least a chance at becoming Bonsai stock.
In order to better turn the bulge into an asset rather than a liability, there are two things I will do here: [1] Ensure that the layer site is located at precisely the widest point on the bulge; and [2] Use a method known as a 'skirt layer' (more info here). So here goes...
Using an appropriate tool for the job (in this case, a cheap paint scraper with a new 'Stanley knife' blade inserted), a single cut is made around the entire trunk at the widest point of the bulge. (Rather than slicing the bark, it is preferable to press the knife edge straight into the bark and rocking it from side to side. In many cases, there is a noticeable 'pop' when the blade has penetrated the bark to sufficient depth.) Another cut is made about 15-20mm below this, and the two cuts are joined by a vertical cut. (A standard rule of thumb when layering is that the width of the ring of bark to be removed should be 1.5 times the diameter of the trunk at the layer point.) The resultant ring of bark is then removed from the trunk - if the cuts have been made correctly, the ring will pop off with no need for cleaning up the wound.
Here is where the 'skirt' method differs from standard air-layering: above the site where the bark has been removed, a number of vertical cuts are made so that the bark may be lifted (like the pleats on a skirt). In this case, I recall 7 or 8 cuts were made, each about 5-6mm apart.
Traditionally, the lifted 'skirt' is held in place by means of a ring of wire which is pushed up and under the flaps. Far be it from me to be stifled by tradition, I have come up with a much easier and safer way to get the 'pleats' to lift and stay in place: the humble tiler's wedge! They are so sharp at the point that they are easily inserted under each individual pleat, and their taper allows the pleats to be gently lifted to the desired point.
Initially, I had intended to wedge every second flap in order to create a more undulating root flare, but decided that a Euc like this could use all the help it could get in trying to achieve a nice Nebari. In the end, I wedged every flap except the one where the original wiring injury had occurred, as the bark there had grown into the broken heartwood, making it impossible to safely lift the flap (refer to the 3rd and 9th pics). Using 3 heavy duty garden ties fed into each other around the trunk, I created a platform which would help support the layering pot.
The split pot was then carefully placed around the trunk, duct taped back together, and gently filled with a 50:50 mix of chopped sphagnum and my standard Native Bonsai mix, so as no to disturb the wedging.
Now all I can do is water and wait. (Hopefully the layer takes, or else I'm gonna look like an idiot...)
Thanks.
Fly.
when did you do this work fly 
). Each pleat then had a wedge placed beneath it, but you can see that this has had little effect on the flare of the layer.