Wiring is an essential technique to create beautiful bonsai. It is not the only means (as some practice the Lignan method of cut and grow) but it is the most efficient way to shape a tree; to open up foliage to let light in; to move branches/trunks into place.
However, many inexperienced enthusiasts, and even many experienced ones, make certain mistakes in wiring that is evident in their technique. I am not going to outline all of these deficiencies but want to mention one often overlooked. First of all, if one wishes to learn proper wiring technique, there is no substitute for practice, practice, practice AFTER you first learn proper execution from a good teacher. Then just do it and do it some more (and then do it some more!)
But what I wanted to comment on in this post is the often practiced action of taking wire off too early. I know some practitioners who are so quick to point out wiring scars, however minor, and then diminishing the artistry of that particular tree off hand because of this.
Lets try to understand the process of putting wire on a branch to shape it and keep it in that new position or shape. Every species reacts differently to the effect of wiring (and that also can only be learned from experience) – how long it takes for the branch to hold it’s place by itself, how long before the wires start biting into the bark; how big a wire to use, how tight, etc.
In general, once the wire is applied and the branch is moved into place, it is the action of the branch growing and the cambium swelling a bit on that branch – in that new position – before it will hold there on a more permanent basis. Pines and Junipers take a while to hold their branches into a new position and wire can often be kept on for 1+ years to achieve this. Maples swell quickly and branches wired in early spring may have to be removed in a month or so.
However, it is often taken off too soon because we are afraid to cause any scarring. This is a misconception. Letting the wire dig slightly into the bark (or rather letting the branch swell a bit to cause the wire to dig slightly into it) is often necessary to achieve a good hold in that new position. Experience shows that a healthy growing branch will allow those minor scars to heal over in a season or two. (Notice I am only saying slightly – major digging into the bark can be a long term problem that may not be correctible unless it is disguised or hidden).
There was a visiting master to our nursery who was hired by a customer to completely wire out their very nice black pine. It took about 4 hours of work to achieve a very beautifully shaped tree. A few months later this customer brought the tree to a workshop at the nursery and had already removed all the wire! – from a black pine no less! It should have been kept on for a lot longer.
One common myth is that there are no trees in Japan with any wire scars (just as the other myth that trees in major shows have no wire on them). It all depends on the stage of development that a tree is in. To make branches stay in position on a younger developing tree, you must allow the wire to bite into the bark slightly for it to stay in place. One the tree is closer to the refinement stage and detail wiring is executed, these older minor scars are healed.
You can only really learn this by practice and making a few mistakes until it becomes ingrained in you.