Wiring for Bonsai
By Lawrence LeClaire, BSSF
Why we wire trees for bonsai?
There are many techniques to introduce movement in the trunk and branches of our trees. These include braces, trunk benders, guy wires, and clip-n-grow. However, the most useful and effective technique is wiring. By using wire, the bonsai artist can introduce dramatic bends in the trunk or branches of a tree that far surpass other techniques and achieve permanent results much quicker.
What trees are wired?
Typically, most trees can be wired for bonsai. However, certain trees may require extra care or a specific type of wire. Nearly all conifers (black pines, junipers, etc) respond well to wire. These trees have flexible branches and bark allowing for deep bends and radical movements. Copper wire is recommended for conifers because it is strong and once bent, remains in place. As for deciduous trees (maples, elms, beech, hornbeam, etc), greater care must be used when wiring. Branches on these trees are sometimes brittle and the bark is easily scarred or removed. Sometimes aluminum wire is recommend for these trees or even paper-wrapped wire.
When do we wire?
Wiring bonsai is usually location and species specific. In San Francisco, where the nights are always cool and most days are humid, trees are less likely to dry out from loss of moisture through minute breaks and cracks along freshly bent branches. Therefore, our wiring season is much longer. Where the weather is much warmer and dryer, trees should be protected after wiring from drying winds or direct sunlight for a few days until the tree stabilizes and the wounds seal. Sometimes, bonsai artists mist freshly wired trees with water for a few days after wiring. However, in San Francisco, where the fog is too common, we generally try to keep our trees a little dryer to prevent mold/fungus/disease and therefore misting is not recommended.
When deciding when to wire a tree, we must consider the species and growing season. Typically, we wire trees either while dormant in the Fall/Winter or after a growth spurt in the early to late summer. Junipers, which grow nearly all season, can be wired all year long. Pines are wired in the late fall/winter for a variety of reasons. Mostly, because wiring in the summer may disturb precious back buds along branches. Maples and other deciduous trees are wired in the fall/winter and in early summer. Typically, wiring in the summer is to position green branches before they harden off and become inflexible.
MOST IMPORTANT: The health of the tree is the most critical factor to consider before wiring a tree. Bending and flexing branches causes a great deal of stress in a tree. Therefore, if a tree is unhealthy, you should wait to wire.
In most cases, buy local and support your neighborhood bonsai supply merchants. However, if you need to order online, consider these options for purchasing equipment and wire.
1. Dallas Bonsai – Aluminum wire and Fujiyama and Masakuni tools.
2. Jim Gremel – Dear Meadow Bonsai – Copper wire, handmade pots
Copper wire. Copper wire for bonsai is always annealed prior to use. This process softens the wire and makes it more pliable for wrapping trunks and branches. Once bent, annealed copper wire hardens and holds the trunk/branch in place. The copper color oxidizes over time and the dark color blends in with bark of the tree.
Aluminum wire. Aluminum wire is much softer and has less ‘holding’ power than copper. However, the softer wire is often ideal for the fragile branches of some deciduous trees. Aluminum wire is often copper-colored to blend with the bark of the tree.
The right tools for the job…
Wire cutters. Wire cutters for bonsai are not your typical Craftsman/electrical cutters found out Sears. You should purchase a pair of wire cutters designed specifically for bonsai. These cutters have blunt ends that prevent damage to the tree’s bark when removing wire. Also, these cutters have long handles to reach inside the crowns of trees.
Pliers. Pliers in bonsai get no respect. They are the workhorses of the bonsai toolbox. Often they are the most used tools a bonsai artist owns however they live in the shadow of the more ‘sexy’ bonsai sheers or concave cutters. All bonsai toolboxes should have at least two pairs of pliers. Pliers for bonsai have long handles for greater torque, reach, and grip.
Copper has an infinite recycling life meaning your bonsai wire today can be an air conditioning unit tomorrow. Copper’s recycling value is so great that premium-grade scrap normally has about 85% of the value of the primary metal from newly mined ore. PLEASE RECYCLE.
Copper wire scraps are excellent projectiles when propelled by a whirling lawnmower blade/weed eater. Even a few runaway pieces on your kitchen floor may find a way into the sole of your bare foot at 2AM on the way to a late night snack. Therefore, be careful when clipping wire and collect all the cuttings. Some people may also suggest safety glasses. Many of us have seen wire cuttings fly into the air when trimming, so wearing safety glasses can be a good idea.
1. Wire size – Choosing the correct diameter of wire for a branch is critical. Too small and the wire will not hold. Typically, you should choose wire 1/3 – 1/2 the diameter of the branch to be wired. As a rule of thumb, when using copper wire, pick wire 1/3 the diameter of the branch and for aluminum, ½ the diameter branch. Err on the side of the larger wire.
2. Length – Cut and additional 1/3 – 1/2 length of wire than the branch to be wired. Don’t skimp.
3. Anchoring: The ability of a wire to bend a branch is completely dependent on whether the wire is anchored correctly. Without proper anchoring, the wire cannot hold the branch in position. So, before wiring any branch, you should study where and how the wire will be anchored. The most popular places to anchor a wire are:
A. In the soil/roots (for trunks)
B. To an adjacent branch
C. Under another wire
When anchoring a branch, also decide which direction the branch will be bent. If the branch is to bent downwards, bring the first loop of wire over the top of the branch. If the branch is to be wired upward, bring the first loop of wire under the branch.
4. Wrapping: When wrapping a wire around a branch, the coils should be evenly spaced between a 40-60 degree angle. Wire wrapped outside this range of angles is inefficient at holding bends. Try to anticipate where the bends will be in the branch and wire to the outside of the proposed bend. The wire will support the bend and prevent damage to the branch. To wire a branch, position the tree so that the branch is protruding out toward your body. Next, grasp the branch with one hand to support it. Use your other hand to spiral the wire around the branch working towards your body. Alternatively, you can use two pairs of pliers to both support the branch and wrap the wire. This is particularly useful when wiring thicker wire. After the wire is anchored, grasp the wire with one pair of pliers. Next, work the wire around the branch with the second pair of pliers. This technique also helps to prevent tight wiring because without your fingers in the way, you can monitor the wire as it touches the bark.
5. Bending branches: Once the wire is wrapped around the branch, it is time for positioning. When bending, never bend the branch directly. Instead, use pliers to bend the wire. With thicker branches, sometimes a small bit of stretching of the branch is helpful prior to wiring. If you anticipate that the branch will crack or break, wrap the branch with raffia.
6. Wire tightness. Typically, we wrap thick wire too lose, and thin wire to tight. The Japanese teach that a sheet of tissue paper should slide between the wire and branch. However, no matter how you try, this is impossible. If you succeed, you will be awarded the Noble Prize in engineering. In fact, the wire must contact the tree in order to the bend a branch. The most useful verb to describe how to wire a branch is ‘lay’. Instead of wrapping a branch with wire, you will be ‘laying’ the wire around the branch. So, as you move the wire around a branch, take care not to use the branch to bend the wire. Instead, use your fingers or pliers.
7. Order. Begin wiring a tree at the base and proceed to the apex. First, completely wire the main branches followed by the secondary branches and finally the apex. By following this sequence, you will avoid incomplete wiring.
8. Remove and clean excess vegetation. Before wiring, you should clean your tree thoroughly and remove any excess growth. Removal of this material will allow easier access to the branch for wiring.
9. Wire removal. Pay close attention to a tree after wiring. Remove the wire once it begins to bite into the bark. Junipers and pines recover well from wire scars but deciduous trees do not. During growth spurts, wire may scar a branch in as little as two weeks. Therefore, wired maples and other deciduous trees should be monitored continually. Check each branch thoroughly after removing a wire. Sometimes, a small ringlet of wire may be hidden within some vegetation. Unnoticed, this small ringlet of wire can seriously scar a branch or even result in loss of the branch.
10. Practice. Learning how to properly wire in bonsai is difficult. The best way to become proficient at wiring is to practice. Also, take your time. It is not uncommon to spend 8 hours or more wiring a small tree. Your tree will benefit from the proper application of wire. Have fun!