Chapter 38 Deadwood Features: Jin, Shari, Uro and Sabamiki

Creating deadwood on bonsai, in the form of jin, shari, uro, and sabamiki can enhance the tree’s character significantly. Jin and shari look appropriate and natural on conifers, while uro is most appropriate on deciduous and broadleaf species. Sabamiki can be applied to both conifers and deciduous species.

All of these deadwood techniques should be used judiciously and after careful consideration. Once started they cannot be reversed.

Jin is deadwood on branches or the leader of the trunk. On wild trees it is caused by wind, lightning, or other damage. Jin on a bonsai requires completely removing the bark from a given start point to the end of the branch or leader. The exposed wood dies and dries out to form the jin. Jin on the leader produces a shorter, more visibly tapered bonsai in a single step. Removing the leader shifts energy to lower branches, which grow more quickly and help increase trunk diameter. It also is an aesthetic solution for a tree with two leaders. Branches converted to jin remove unwanted branches while increasing the illusion of age.

Shari is deadwood running vertically on the main trunk of the bonsai. In nature, shari forms when lightning runs to ground, killing a segment of the trunk, or when a branch breaks and tears the bark down the trunk. Sharamiki or driftwood style is an extreme form of shari, where most of the tree is dead, and only thin strips of living bark connect the roots and green areas.

Closely related to sharamiki are tanuki bonsai. Tanuki are made by carving a channel into a piece of deadwood then anchoring a living tree in it to create a composite in the driftwood style. The living tree (usually a young juniper, because of the species’ vigor, flexibility, and ability to endure harsh shaping) is fixed in the channel using non-reactive nails or screws, wire wrappings, or clamps. Over time, the young tree grows into the deadwood channel, which disguises the fact that it is a separate entity. Once firmly in place, the nails, screws, or other affixing devices are removed, and the living tree is cultivated and shaped with typical bonsai techniques.

Sabamiki means “hollowed trunk” or “split trunk.” It mimics a tree that has been split by a lightning strike or other severe and deep trunk damage. The hollowed area may start and end part-way up the trunk, or it may start with a wide opening at the base of the tree which tapers to closure partway up the trunk.

Uro mimics a hollow in a tree where rot has removed parts of the tree’s heartwood. On full size deciduous and broadleaf trees, dead branches quickly rot and fall off, leaving a small indentation where the branch used to be. New wood grows around it, forming a small hollow. Rot and animals can deepen these hollows over time. Bonsai stylists can use uro to cover pruning scars on trees like American hornbeams and gingkos that tend not to heal over well. Uro also can improve trees like crabapples that tend to have natural cavities

38.1 Creating Jin

Hint: use some branches pruned from a tree in your yard to practice your technique before starting work on a bonsai tree.

Select the branches to be carved and how far back to extend the deadwood. If you want to preview what they will look like, paint each branch with a paste of white flour or cornstarch in water. This can be washed off with the garden hose once you have picked your work area.

Use a sharp knife to cut through the bark until you can see the green cambium, all the way around the branch. Make the cuts towards the end of the branch. Lift the edges slightly with the blade so you can pull them away.

Using a hemostat or needle nose pliers, grab one of the upturned pieces of bark, and pull it towards the end of the branch. Try not to pull off any underlying wood just yet. Work around the branch until the bark has been stripped from the end of the branch.

Turn the blade of the knife perpendicular to the branch and scrape off any visible green cambium. When finished you should only see bare wood.

Repeat the same process to strip the bark from any other branches being converted to jin.

Do not carve the branches further just yet. Step back and take a look at the stripped branches in the context of the entire tree. Even if some branches seem too long, leave them alone for now. Come back and look at the tree several times before shortening any branches.

Once you have decided how short to make the deadwood stubs, cut each branch off with pruners, about 1/4-1/2 inch longer than the final desired length. Use a knife or pliers to lift a few fibers from the previously exposed wood, grab them with needle nosed pliers, and pull them towards the cut end of the branch. Repeat this process as needed on all sides of the branch, working towards the tip. The goal is to create a tapering, textured stub that comes to a blunt point.

After the taper is roughed out, use fine sandpaper to knock off any stray fibers. Don’t over-sand the tapered wood; it should be unevenly shaped, as if broken and worn over several years.

Once shaped, let the green wood dry out thoroughly before applying a wood preservative.

A Sargent juniper showing both jin and shari. Link to original image

38.2 Creating Shari

Shari is much more challenging, and there is a significant chance of cutting the stream of nutrients to an important branch. It should be done very slowly over months or years.

I’ve never done it personally, so I’m sharing directions from Bonsai Empire - link to original story.

Choosing the right spot for a shari, not only one that looks good but also doesn’t cut off an essential stream of nutrients for branches located higher in the tree, is very difficult.

Before you start removing bark, draw the desired shape of the Shari on the trunk with chalk.
Do not take any risk and spread out the process of creating a Shari over the course of several months, if not years; start with a narrow strip of bark which you can widen in stages.
Cut through the bark with a sharp knife. Follow the live vein upwards from the base.
Remove the bark carefully using jin or needle-nose pliers. The shari should continue into the soil for a natural appearance.
Once the desired shape is ready you can slightly hollow the trunk using a concave cutter or graving tools.
Protect the exposed wood with lime sulfur (for conifers) or a natural colored wood preservative (for deciduous trees).

38.3 Creating Uro

A tree with a uro cavity. Link to original image

I’ve gently edited these very good instructions that originally were published on the Bonsai 4Me web site - link to original story.

When pruning faster healing deciduous branches, it is common to prune flush to the trunk, hollowing the wound very slightly. However, some deciduous species do not produce scar tissue readily and are very slow to heal over wounds, resulting in an unnatural flat scar. In other situations, wounds can be so large (particularly after trunk chopping) that it is unrealistic to expect the wound to heal over in less than 10, 20 or more years. Rather than leave the wound as is, it is made into an interesting deadwood feature.

Using an ordinary drill or Dremel tool and grinder bit, hollow out the area where a cut was made or a branch was removed. Don’t make the hollow symmetrical or round; it looks more natural if the shape is somewhat random.

Initially the exposed wood is pale colored. To protect and color it, paint the cavity with either:

Liquid tannic acid, followed by liquid ferrous sulfate (a more natural color);
Lime sulfur mixed with black acrylic paint or India ink (a darker color).

Before creating a uro on a bonsai, always consider whether it would be appropriate for the tree. Uro is appropriate on rough, rugged specimens but not on more graceful species like Japanese maples, or trees that can heal over large wounds readily.

Keep in mind that:

Once a wound has been converted to a uro, there is no going back; the wound will never be able to heal over smoothly.
Large wounds on deciduous and broadleaf species can be painted with acrylics or covered with pieces of bark from the removed portions of the tree.

38.4 Splitting a Trunk For Sabamiki

Examples of sabamiki. 1. Larch sabamiki. 2. Sabamiki and sharimiki combined on a tropical species. Link to original image 1; image 2;

This technique requires a very specific tool called a trunk splitter, which looks like a ceramic tile nipper tool or heavy duty end-nipper pliers. The split may start part-way up the trunk and extend to the top of the tree, or it may start with a wide opening at the base of the tree which tapers down then closes part way up the trunk.

Split trunks. 1. A naturally split trunk olive tree. 2. Basal split in a tree. 3. Gingko bonsai with several split areas in the trunk. Link to original image 1; image 2; image 3.

It is essential to plan the path of the split carefully; after the first cut, it is extremely hard to make adjustments.

If the split will pass through the roots, un-pot the tree, and remove as much soil as possible. Wet the roots and keep them moist while working.
Use chalk or a permanent marker to draw the path of the split on the trunk. Mark BOTH sides of the trunk. If splitting through the base, make sure the path will pass between large roots; do not split a large woody root.
After finalizing the path, use a sharp knife to remove a 1/4-inch wide strip of bark along the path on each side of the trun. This will make it easier to split the woody portion of the trunk and reduce the chances of tearing the bark.
For a basal split, start at the base of the trunk and work up to the point where the split stops; for a top-split, start at the apex and work down. Open the trunk splitter and put the jaws in the middle of the de-barked path on either side of the trunk.
Squeeze the handles so the jaws bite through the wood. Open the jaws, rock the handles to loosen the tips, and remove the jaws from the cut.
Move up or down about 2/3 the width of the jaws, line them up on the cut line, and cut the trunk again.
Continue working up or down until the trunk has been scored the full length of the pre-cut path. Do not try to pry the two sides apart yet; after the first pass, the trunk is probably not split through completely.
Go back to the starting point and make a second pass, cutting through the remaining wood fibers.
Put a thin dowel, chopstick, or pencil in the split, perpendicular to the trunk. GENTLY and SLOWLY roll the “wedge” into the split to separate the halves.
If the tree was un-potted, repot it as soon as the wedge is in place. Small splinters can be removed, but otherwise give the tree several weeks to recover before doing any additional carving.
The wood still is green right after splitting the trunk so does not need immediate preservation. Let it dry and season for several weeks before applying preservative. I’ve written a separate section exploring how to choose the appropriate preservative from a range of options.