How do you simulate old bark ?

[JohnW63]

Vance,

I understand that point of view. It still seems that if left to it's own devices, most bonsai would "prefer" to be larger, have more roots, and send branches all over the place. It's by our efforts that it retains the size and shape we want it to have. I suppose the goal is to keep it as healthy as possible in it's confined environment. When I read statements like, " Watering your bonsai is not that simple. " I begin to wonder if they are more on the edge than normal.

But, I'm just a newbee with not a single tree in my collection.

 

[Smoke]

I think there is a lot more to say on this subject. I think to have a real factual discussion, the parameters should be discussed.


Are we talking about diciduous trees or conifers?

Vance states his vast 50+ years at developing bark on a species that is genetically predisposed to develop fissured bark all on its own. All conifers will develop craggy bark when they reach the particular age that fissured bark in its genetic makeup is reached.

On diciduous trees this is not very possible. Most diciduous trees never develop craggy bark due to the thinness of its bark. It is more elastic and does not contain the resinous sap that keeps a conifers bark intact. Diciduous tree while containing sap, tends to be more of a sugar water solution rather than containing the esthers and ketols contained in conifer sap.


Bark is not built from the top down. It is built from the core. As the core grows it expands the girth of the tree causing older skin (cambium) to crack and exfoliate. In diciduous trees this falls off in patches like on tridents and elms. The under skin is sometimes brite orange on both species. On conifers this cracking is held in place by the resinous sap. As the resin drys it hardens into a very hard almost glass like substance. On junipers this outer bark can be peeled off extremely easy due to this outer layer floating on a layer of sap. Once this area dies, the sap hardens and it becomes very difficult to remove the bark a year later. Ted Matson suggests watering the old areas of dead trunks and branches everytime the tree is watered and the water slowly dissolves the sap and releases the bark. I have used this method myself on old california junipers where the bark is impossible to remove , but very easy after a couple years of watering.

Poink has actually stated some very good facts about the technical aspects of bark growth. I am not so sure about Vance's 50+ years of producing better bark charecter by keeping a plant root bound. Mugo's will develop bark at the right time no matter how they are cultivated.

In my experience trees do not usually start producing bark until the tree is in a situation where the trunk does not expand outward and fast as the new bark can form to cover it up. In other words keep it in a pot and let it get really old and root bound.

I think this statement needs some clarification.

A tree does not form bark. Bark is just dead cells, just like our skin constantly sluffs off. As the tree constantly grows, the older areas crack as the girth expands. The cambium under the bark is what is growing. On many ttrees like elms and tridents this camium is very close to the surface. So much so that soft fingernail pressure is all thats needed to dig into the green growing area. One can hardly call this bark. For the life of the tree even large trees with one foot thick trunks will be very smooth.

 

[Smoke]

This small trident maple was the recipient of squirrel damage last year. The tree was actually girdled all the way around. One of the neat aspects of this tree was due to its small size and its pretty aged bark for a small trident of only 5 inches tall.

One can see the stretch marks and cracking of the skin as the tree has grown. The tree is old enough that the bark no longer flakes off but has formed a rather rough textured skin.

 

[Smoke]

The lower part where the damage was is repairing itself. The cambium is rolling around the damage and will close up probably next year. It will take another five years for the area to match the upper portion of the tree.

That third picture shows a side of the tree where the cambium is really growing fast. It has repaired all the way from the upper part of the damage to the root area of the tree. This is not bark. This is new cambium, skin. It is after a few years as it devlops another season of cambium under this layer that the upper, last years layer will dry and crack as the tree expands.

 

[Smoke]

This is the trunk of a thirty to fourty year old elm tree. The bark is fairly smooth and some of the exfoliation I spoke of has happened this year revealing the orange patches I spoke of. It is rather smooth with small bumps and soft texture.

 

[Smoke]

This is the trunk of only a six year old cork bark elm, ulmus corticosa. In only six years the outward appearance of the bark is much more rough and beginning to fissure vertically along the trunk.

The thirty year old elm has smooth bark because thats what it is predisposed to have, while the six year old cork bark elm has very rough bark because thats what it is predisposed to have.

Bark is all genetics.

Ask a pine groupie about the predisposition of bark on Mikawa pines. When its time it will grow all on its own.

 

[jk_lewis]

I think time is paramount in any development of old bark. Here is a shohin pear that started as a seedling in 1995. I split the trunk when it was about pencil thickness, then wired the two halves apart. That is the only work I did on the trunk -- certainly no scarifying or other disfigurement -- so the old bark is a product of time alone.

This picture is from spring 2013.