Monday, 23 January 2017

Post 231 Trunk thickening

Six months ago I wanted to take a picture to support a description of the air layering process for my book, 'Bonsai Foundations'. So I cut a ring of bark from the sacrificial branch on a Ficus natalensis, also featured in the book. At the point of the incision it is probably 25 to 28mm diameter.

Here it is with the bark removed. After taking the photo I returned the ring of bark and bound it up with grafting tape. The branch never missed a beat and very quickly healed/sealed up the cuts. On the following photo you can see the cut site and the swelling that arose from the recovery.

I struck this tree from a small cutting in 2012. That makes it 4 years old. The sacrifice branch has made a big difference to the development of the trunk and taper.

 This is a closeup of the site and you can clearly see the callus tissue that has formed in the cuts to seal it all up. It has produced an interesting swelling. Impact or penetration damage to a tunk has been known to result in swelling repair and this can be a useful way to address reverse taper.

 This is the start of a new experiment further down the same branch. This time I'm cutting out a crown shaped piece of bark. Here it is cut around the edges.

 This is the piece of bark removed.

 And where it came from.

 Here it has been returned.

 And then finally bound up with grafting tape while it seals up and recovers. I'll post the outcome in a couple of months time. The experiment is to assess the value of doing this at ground level of a trunk with limited taper.

Friday, 20 January 2017

Post 230 Tree structure - UK Visit #3 - Low divided trunks

This is the third and last in this series of three posts on Trees in the UK winter. I've been reflecting on the structure of deciduous trees, looking at the range of variation in trunk division from high to low as in these sketches from 'Bonsai Foundations'.

This post shows a series of pictures of trees with low trunk division. These are all good authentic legitimate models for deciduous bonsai design.

Thursday, 19 January 2017

Post 229 Tree structure - UK Visit #2 - Mid divided trunks

Here are some more trees from my UK trip, and the Bonsai Foundations sketch of various trunk division models.

When grown out in the open a tree does not face the pressure, proximity and competition of other trees and it is more likely to break out of the dominant single trunk model. This one has divided close to where the first branches emerge. It is almost a natural broom style except that the divided trunks divide further still. It has a nicely rounded canopy, shared by many branches.

This is one of the more attractive in this post set. It has complex ramification, great movement, fan architecture and a great rounded form.

In bonsai we take natural patterns and improve on them to create an idealized model. In this tree there are a number of visual conflicts in branch directions, if it were a bonsai. But if you visually filter out those distractions (two in particular) the balance of the composition with a divided trunk is an interesting useful model for authentic design.

Tuesday, 17 January 2017

Post 228 Tree structure - UK Visit #1 - High divided trunks

In "Bonsai Foundations" I discussed at length the matter of authentic structural design of non conifer bonsai, in particular the 'architecture' of branches and trunk. I looked at a variety of models existing in the natural world that should be embraced in bonsai design.

 The first point to note is the 'fan' branch configuration from downwards around the lower margin to more upwardly inclined in the canopy, which prevails regardless of the trunk structure. This is also a pattern which is very prevalent with conifers.
The second is the nature of the trunk, from dominant single trunk through to divided and where divided, the different levels of division.

In looking at trees these are the things to look for, to carefully observe.

In the book I created three sketches to illustrate the point. Here they are again.

I've recently been to the UK, in the middle of the northern hemisphere winter. The days may have been short and the weather cold and damp, but the trees were magnificent in their leafless state. 

 To start with a picture of a tree which follow the high divided trunk model of the sketch on the left.

But it is much more common in mature trees which are close to their maximum height to see the trunk divide further down the tree as in the second sketch.
This first  one is a great study of a deciduous tree's canopy. Its hard to see the rest of the tree but you get a sense of the fan branch configuration, with the lower branches closer to the horizontal plane. In the canopy the dominance of any one primary trunkline is diluted by the mass of fine branches with an upward inclination. As a model for bonsai this means that the canopy is shared and supported by many branches and because of their number none gains in disproportionate weight.
 Here is another one with the upper division and a similar fan branch configuration. Note the three dimensional nature of the branch structure - there are no flat 'pads' anywhere. Also the number of branches from further down in the tree that go out and upwards each looking for a place in the canopy.

 This is a nice study of a close pair of trees, one a beech, still holding on to its old leaves, and the other an oak. There are many aspects of design here useful to building authenticity into your bonsai, divided trunks, shared canopies, upward and outward branches etc.

Monday, 16 January 2017

Post 227 Swamp Cypress graft incorporation

Back in September last year at the start of this growing season my Swamp Cypress trees took off after their winter break. The one in the pictures below produced an adventitious shoot in a place where I didn't want a new branch and under normal circumstances would have just removed it as a matter of course. But there was a branch gap just above where a little more branch density would add to the composition so I allowed the shoot to develop and wired it into a loop early to place the new branch where I wanted it..
By late October it was ready to graft.
I wasn't able to execute a full hairpin so went for something that was closer to an approach graft. I made a groove in the trunk about the depth of the scion diameter and shaped to match the U shape of the bend in the scion at that point. A nice tight fit makes for a faster union.

 In this picture you can see where the shoot emerges from near the junction of another branch and the trunk. From there I took it up and around and under to bring the scion and trunk into the right proximity and orientation. I couldn't get a full 180 bend so went with an open U shape of about 60 degrees.
By January the graft has taken well and the new branch tightly incorporated. As a half way house to full separation and removal of that loop I've cut a wedge out of it to diminish any contribution it is making. 

Here is another picture from the side showing the tight incorporation of the scion and trunk. The join will be very neat in the future and it is placed at the rear of the trunk. By the end of this season the junction will have callused over and look quite natural. I'll take the loop out fully in another couple of weeks. The structural integrity of  the graft junction makes the new branch quite secure.

So after about 2.5 months I have a new branch of the right proportions filling a gap that would otherwise take away from the composition. Fast, easy and a great result.

Inadequate branch density is a major failing of many bonsai, where they have been developed too quickly by simple styling of available material with limited cut and grow. See Bonsai Foundations on Facebook