Some Notes from Marco Invernizzi's 2008 Visit

by By Aaron Khalid
Photographs by Mike McCallion

On Sunday April 13th, I attended Marco Invernizzi's afternoon workshop and evening demonstration at the Royal Botanical Gardens. Below is a brief summary of some of the technical and philosophical points I was able to take away from Marco's visit, loosely arranged according to topic. I hope that this information will be helpful to those who were not able to attend this outstanding event.

Trees

* Health is the #1 priority.

* Tree must be absolutely solid in the pot.

* Take your time with everything; only work on a tree if it is ready.

* Tool marks are bad.

* Be nice to the tree: clean it up, cut off dead twigs/branches, and don't leave the surface roots buried.

* A tree in a pot is not a pre-bonsai.

Tools

* Branch pruners and concave cutters are the most important tools to keep sharp.

* A strong, stout grafting-style knife is important for cutting bark. It doesn't have to be too sharp as this will make it more dangerous but not more useful.

* Markers for outlining shari are useful.

* 'Root cutters' are actually for splitting branches - these are a great tool.

* Tools required for working on dry deadwood: a sharp stubby chisel, a light mallet, and good pliers.

Wiring

* Copper is the best for conifers. Period.

* Softer aluminum is best for broad-leaf deciduous trees.

* Wiring is an essential aspect of creating conifer bonsai.

* Ergonomics: stand up when wiring with the branch 45* to the side (left or right handed), at belly height. Being comfortable is important because it makes wiring that much easier

* If right-handed: left hand holds wire solid against branch, right hand turns the wire. The dominant hand holds wire at the tip for maximum leverage, Practice makes perfect.

* Wire one branch at a time - don't jump branch-to-branch. Rather, pick one branch and wire the whole thing (primary, secondary, tertiary...) so you don't have to constantly re-analyze each branch for a wiring strategy. This saves a lot of time and lets you do a better job.

* When you reach the end of the branch, the wire should face up and back.

* Don't be reluctant to spread a wiring job out over a long period of time (hours, days).

Quality work is important so you may as well just take your time and do it right. Bending branches

* When preparing to bend a thick branch on a juniper, flex it gently for awhile in the bending direction (like stretching a muscle) to soften it up before actually wiring it and bending.

* Raffia is good because it breathes, tightens when it dries, you can make it to the required thickness, and it starts to decompose soon after the job is done such that the tension is very slowly released.

* Raffia is applied in "bundles", not in individual strips. Take 6 to 10 strips, of approximately equal length, and put them together in a bundle with a knot at each end. Start wrapping well below the point at which you will be bending, similar to anchoring a wire. Overlap each wrap with the previous one, so the branch is completely covered. Each wrap should be pulled very tightly, but there is no need to maintain tension continuously as you apply the raffia. Knot the raffia around the branch when you have reached the end of the area to be bent. Creating Jin

* Deadwood if the grain doesn't actually go in that direction (well, you can, but the tree will likely die). No power tools needed when the wood is still alive (just shears and pliers!).

* Best done when the branch is still alive because it is so easy to work with and you can bend the jin dramatically.

* Strip all of the bark and cambium.

* Texture can be added to the jin by peeling layers away, revealing the grain of the wood (snip with scissors _ peel with fingers or pliers).

* Finish with a small torch, primarily to remove unsightly slivers of wood

* You can wire and bend jin in essentially any direction if it is fresh. It doesn't really matter if it cracks and breaks, it will look good and the wire sort of holds it all together. It will hold its position when it dries.

* If you want to make a dramatic change of direction at the base of the jin, a good idea is to split the base of the jin with the splitting tool, about _ of the way through (horizontally and vertically in cross-section), then bend.

Creating Shari

* Outline the planned shari with a marker then slice the outline, cutting at a 90* angle to the trunk _ strip bark and cambium.

* The chisel, mallet, and pliers can be used to create dramatic valleys in the deadwood, which will create nice contrast and shadows.

* Hammer in the chisel at a 90* angle parallel to the grain of the wood and pry out the valleys bit by bit.

* Again, this is much easier when the wood is live.

* If a lot of material needs to be removed you can use a power tool, but finishing work is generally best done by hand.

* Always follow the grain of the wood... you shouldn't make spiraling cuts.

* Finish with a torch.