Okay, I've read the books, etc. and have seen the pictures on doing this... BUT...
Is this just a single loop of the aluminum wire around the trunk, so that it gives as it thickens? Must it be aluminum wire? Does this work on all types of trees?
Thickening a trunk
I use different gauges of annealed copper wire. Mostly #16, #14 and #12.
You wind it arount the stem or branch at a shallow angle, i.e. stretched out coil or helix.
BassetMom,
I don't understand what you are trying to accomplish. Are you trying to get the trunk to thicken? If so, the best way to accomplish this is to plant it in the ground for a few years. Then, a few months before taking it out, use your shovel to cut the surface roots all the way around the tree about a foot from the trunk. This will encourage new feeder root growth.
If you can't plant in the ground, the next best way to thicken the trunk is to leave side branches on as this helps the trunk thicken and repot into the next size as soon as the roots have filled the pot. Do not overpot.
Wire does not stretch enough to expand as the tree trunk grows. Wire is use to train branches into the desired position, but has to be replaced as the branches grow or you will get a disfiguring rippled effect. The extreme effect would be girdling of the branch or trunk. Copper is recommended because it is more malleable.
Bettydee...
In my bonsai book it shows that the base of the trunk should not be too thin. They show wrapping a piece of wire around the base, not to tightly but tight "enough" to encourage the trunk to thicken. This in for a tree already in a pot. My store-bought tree has a rather puny trunk and I thought I would try this but didn't know from the pic in the book exactly how.
Hey Mom, either you misunderstand what your book is saying or the writer doesn't know what he/she is talking about.
bettydee is absolutely right.
Hmmm... so much for learning this hobby from a book! I'll just stay right here at DG! I posted the pic of this tree in another thread. Does it look too thin?
Well, we'll need a link to that thread or some other hint, LOL.
This may be of interest to you: http://www.bonsaisite.com/
http://davesgarden.com/forums/t/499004/
This is the tree and trunk in question. Too thin at the base?
It is quite normal for it's age. What you are thinking of takes many, many years.
Another way to spell 'Bonsai' is ' P a t i e n c e '.