As a complement to the roots & nebari thread I decided to start a new thread for opinions about trunk size and tapering effect. Now all we're missing is "Branches and ramification" and "The art of choosing a pot".

1. Is it important for a bonsai to have a very thick trunk?

2. Does it increase the value of the tree if it has much taper?

3. What is the optimal trunk diameter?

I know these questions cannot be answered by saying yes or no, but maybe we'll have an interesting discussion about these matters.


Zeb

Since it's my thread, I'll go first.

On my opinion, a good bonsai has a fairly thick trunk and some taper. The "fairly thick" should be concerned thicker on formal uprights and less thick on literatis or bunjingis.
In general I do not like trees that have too massive trunk diameter (some mini bonsai especially) with truckloads of taper. I like more natural-looking trees with less taper and less trunk diameter.


Zeb

Zeb,

My 2 cents:

1) No, decidedly not. "Masculine" trees and styles benefit more from strong taper than do "feminine" trees and styles; similarly formal styles tend to benefit more than naturalistic styles. I'm a fan of moderate caliper myself, and I decidedly dislike the exagerated trunk diameters that you see on some shohin trident maples and such. And as you say, all bets are off once you look at trees done in the literati style (though taper still is desirable).

2) Probably. Taper is perhaps more important than diameter. Taper suggests that you've got something other than a stick or a sapling in a pot. That said, I don't like the repeated-trunk-chop extreme taper that you see on the aforementioned shohin tridents. All things in moderation!

3) The neoclassical answer is yes: the optimal diameter is 1/6 of the tree's height. For most trees under most circumstances, that seems a bit much to me.

---

Maybe more the point is the following. Taper and diameter are wonderful things on world-class trees. But they are by no means the only important aspects of a tree, and they are difficult if not impossible to develop quickly without comprimising other qualities of the tree. So the 1:6 ratio looks wonderful on the masterpieces at the Pacific Rim Bonsai Collection here in Seattle (see below; I've added a line at the base of the trunk equal to 1/6 of the tree's height.). But on trees of the quality that I own now or will own in the next decade, I suspect that I would be making a mistake to shoot for 1:6 too quickly.

Hi Zeb,

The appropriate thickness of the trunk is wholly dependent on the artistic aims of the artist and has no intrinsic impact on the (artistic) value. Taper, however, does have great impact on the artistic value (and therefore, monetary value) and has to contribute to the integrity of the overall design, much as Old Mister Crow suggested. For instance, a bunjin styled tree HAS to have gentle taper and a not-too-powerful trunk and trunk base or it will not "work." I have a bunjin black pine that has a trunk that is just a bit too strong and this tree, therefore, will never be anything but mediocre.

While tastes vary regarding acute taper or gentle taper (powerful or feminine designs), these compositions are merely references for the perspecive of the view of that tree. In other words:
- acute taper indicates a very close view of the tree
- moderate taper (as in the Beech in OMC's post above) indicates a nearby, but not distant view.
- quite gentle taper indicates a far view.

Per your question, "optimal" trunk diameter is completely dependent on the overall image and its integrity. As my little brother says, "everything is relative" (in bonsai).

Also regarding you question and to the previous thread, nothing, not even taper, will increase or decrease a tree's value so much as it surface root structure (nebari). Take two of the same tree, one with no nebari and one with a great nebari and the difference in price will be 4 - 6 times (as in $100 vs. $400 - $600). No getting around it - and for good reason.

Kind regards,
Andy Rutledge
zone 8, Texas

My position is pretty simple: The trunk has to have movement or taper. No movement, no taper: no bonsai.

When I collect a tree or restyle one, it's easy to know how big the tree should be. Cut the tree somewhere around the point at which the movement or taper stops. You can cheat this a bit if you are good at carving or hide a bit of straight trunk or reverse taper with branches, but the bottom line is that the trunk is the melody and the roots are the baseline, and the tree needs to play.

Regards,

Matt

I pretty much agree with all that has been said. The only addition would be that I much prefer uprights or semi uprights that don't show a drastic trunk chop. Raising trees from infancy where you can keep the chops almost unseen is preferrable. For instance, that maple from the Pacific Rim...I would prefer that it not have been chopped so drastically. It won't be seen in leaf but is sure noticable now.

But again, most of us don't have 100 years to raise a tree from a seedling to get that quality without chops... so in reality this is a "do as a I say, not as I do" comment.

I agree with all of you.

1. Is it important for a bonsai to have a very thick trunk?

It depends on the tree. I have seen pine bonsai with trunks 7" in diameter that were choped and I've just passed them by. Then again there are those trees that you can stare at in amazement and they hypnotize you no matter how thick the trunk is.

2. Does it increase the value of the tree if it has much taper?

I'm with Matt on this one. It either has some movement or taper to a least some degree. I call it personality.
If a tree doesn't have a personality it's brush.
Does it increase the value..............I suppose so, to what degree, I don't know.

3. What is the optimal trunk diameter?

Naka says 1/6. Since I don't like even numbers I'd say 1/7 or 1/9 works pretty well also.
It's all so subjective. As a Landscape Architect I always try to strive for the 3/7 rule for laying out objects in the landscape but there are those times when you go on instinct, and it works....I don't know.

I was waiting at a traffic light today and there was an old burr oak tree I was staring at on the corner, must be 150 trs old. It was so beautiful. I looked at the flare of the trunk, the branches, the crown-perfectly shaped by nature. It was a work of art. I was sorry when the light turned green and I had to go.

There is that word in Japanese that isn't translatable into English. Maybe someone can help me out here, I forgot it. It's pronounced "Gee", I believe. It's in one of my old books, I'll find it.
Anyways, it refers to a bonsai that just has all the right stuff.

Interesting posts, all!

Andy, I'd never really thought carefully about the relationship between taper and perspective - very interesting! Now I better understand why forest plantings rarely exhibit trees with extreme taper: because that would suggest a close-up perspective that would be incongruous with the at-a-distance perspective implied by the forest itself.

One other comment - it seems to me that some styles benefit more from taper and particularly trunk caliper than do others. Throwing out the obvious departure from 1:6 seen in the literati style, we can still find examples. The broom style seems to be one which does not require particularly large caliper, or even all that much taper. Why is this? Is it because the style typically reflects younger trees? Trees which face less in the way of environmental hardships? Or am I plain wrong - does the broom style benefit from caliper and taper just as much as any other?

-Old Mister

Hi Old Mister,

It is just my assessment, but broom form trees in nature don't really have taper from the root crown to the branching (if you're talking about a multi-trunk brooom). Central-leader broom forms do have a pronounced taper, of course. If you look closely at good broom form bonsai (multi-trunk), they have a very solid form. This necessitates a very developed nebari and a consistently directional branching (either curving or straight or more chaotic) where all of the branching does the same thing. The trunk, from the root crown to the branching, is not the "issue" for this kind of composition. It could be argued that a pronounced taper in this area would even detract from the solidity of the form.

In any event, a broom styled bonsai without a very well developed nebari is rather worthless, but the trunk taper really doesn't factor into things so far as I'm concerned. FWIW

Kind regards,
Andy Rutledge
zone 8, Texas

Regarding trunk width/height proportion...

Rules and guidelines for proportions like 1:6 or 1:8 or 1:4 are utterly irrelevant without some reference to a specific perspective for the image.

For instance, it is ridiculous to say that "1:6 is the ideal proportion for bonsai." or somesuch nonesense because 1:12 is "ideal" for many images... even those which that are not literati forms. This would be a very far view and/or a "Pacific Northwest Fir" type image or something. By the same token, this Pac NW Fir could also be portrayed with a 1:5 proportion because the perspecive that the artist is trying to convey is the power one senses when one is standing very close to a huge, tall, yet skinny tree. From this vantage point the tree is very powerful looking and the acute proportion is evident.

Try and get out of the habit of having any specific porportion in mind when making bonsai. After all, it is ART and you should create the proportion that is specific to what you're trying to portray, not to what an innane rule says in some book (and I'm a proponent of most rules!) ;-)

Kind regards,
Andy Rutledge
zone 8, Texas