Wiring is a crucial technique to train and style Bonsai trees. By wrapping copper wire around the branches of a tree you are able to bend and reposition the branches. It will take a few months before the branches are set in their new shape; the copper wire should than be removed.
Wiring can be done year-round for most tree-species. During the growth season branches grow thicker quite fast and as a result the wire will cut into the bark, creating ugly scars. Check on your tree regularly and remove the wire on time.
Using the right material is essential for wiring Bonsai trees. Basically, two kinds of wire can be used: anodized aluminum and annealed copper. For beginners it is advisable to use the anodized aluminum, which is easier to work with and sold in most (online) Bonsai shops. Wire is available in a range of different thicknesses, varying from 1 to 8 mm (see photo 1, below). There is no need to purchase all the available wires; buying 1mm, 1.5mm, 2.5mm and 4mm thick wire should be perfect to start with. When wiring thick branches it is recommended to wrap them first with raffia, which will protect the branches from being damaged by the wire when bending them.
Try to wire two branches of similar thickness located near each other with one piece of wire (double-wiring, see photo 2, above) where possible, and wire the remaining branches separately (single-wiring). Wire all the branches you intend to shape before actually starting to bend them. When wiring an entire tree, work from the trunk to the primary branches and then start wiring the secondary branches. As a rule of thumb, use wire of 1/3 of the thickness of the branch you are wiring. The wire should be thick enough to hold the branch in its new shape.
Both wiring techniques will be discussed in more detail now and information about how to safely bend the wired branches will be provided at the end of this page.
After having wired the entire tree you can start bending and repositioning the branches. Use your hands to hold the outside of the branch with your fingers, now bend the branch from the inside of the curve with your thumbs. This way you reduce the risk of splitting branches by spreading the force around the outside of the branch. When a branch is in position stop moving it, as repeated bending will likely damage the branch. Try to bend straight sections of branches slightly to make it look more natural.
Place the tree in the shade and fertilize as you would normally do. Watch the tree closely during the growth season and remove the wires in time to prevent them from cutting into the bark. Do not try to recycle wire by unwinding it as this might damage the tree; instead, cut the wire at every turn making it much easier to remove.
Guy-wiring is another way to bend branches of a tree downwards, often used when branches are too old, thick or fragile to bend with wire. When using a guy-wire, pressure can be increased slowly, giving the tree time to adept.
Step-by-step plan to guy-wire a branch