Scars, wounds, knots, bumps

grampz

Ms. Nancy,

Many more questions than I will probably be able to answer as slowly as I type, and some will be overlooked I am sure...Hopefully others will pick up the slack...

If you desire to completely close a wound the process should begin soon after the wound is created...Depending on the species and how thick the scar tissue usually forms, the wound should be cut slightly concave, flat, or with a slight 'hump'...The cambium edges should be cut as cleanly as possible with a very sharp knife...I prefer an exacto knife with a new blade, and usually strop it a few times on a hard 'Arkansas' stone [the white one] to give even a finer edge...The entire area is then covered with cut paste...I prefer the model clay type you find in the round flat container [comes in brown or gray]...As the callus forms UNDER the paste it will push the paste away from the wound, yet protect the uncovered wood and keep it moist...Feed the tree aggressively and do not prune above the wound to achieve maximum growth...If the wound seems to stop the healing process, you can remove the old cut paste and once again with a very sharp knife blade cut along the edge of the scar tissue and remove down to the cambium layer, then re-apply the cut paste...I like to do this process each spring until the wound is closed...

Unfortunately the trees you have mentioned here have soft wood that does not hold up well in the aging process, however the trees do have the ability to 'compartmentalize' the wounds and the rotting process will only progress to a limited depth if as you stated the wounds are cut in such a way to not retain water...Lime Sulpher applied to the deadwood will bleach the wood and retard the growth of fungus, mildew, and the like that speeds the rotting process...If you desire a less bleached look you can add 'india ink', or I prefer 'acrylic paint' to the lime sulpher to darken and alter the color of the wood...To further slow the decaying process the dead wood can be treated with a wood sealer type product...'Minwax Wood Hardener' or 'GetRot' are products that I have found very good for this type of protection...I prefer to treat the deadwood with lime sulpher [and color if used] BEFORE I apply the wood preservative products...

When it is necessary or you just desire to leave scars as a feature it is a good idea to carve the edges in such a way that it is not a circle or what is often referred to as a 'bull’s-eye' wound...These are quite un-sightly and un-natural in appearance...Again using the sharp knife blade you can carve the edges of old and new wounds to have a pleasing natural shape, and if you have leaves above the wound apply cut paste to the edges covering the cambium you will likely get a callus to form around the wound making it appear older and more natural...

The cut paste may be ugly but it will only be ugly for a short time...I have used the diluted 'elmers glue' or petroleum jelly if I am covering a very large area such as a trunk chop on a 3 inch plus trunk...This will work fine until you see where the new buds break and you make your decision where you will do your final cut that you want to heal...I could probably write a pretty good book on budget bonsai, but I believe cut paste is one investment well worth the few bucks it costs...I have tried many different products to replace it, but have found none are as satisfactory at promoting healing, protecting the growth of cambium, and staying in place as long as needed yet easily removable...

These are very good questions and books could be written on this subject alone...Different species will require different techniques, and the desired results will necessitate different methods...The time of year you do the work will affect the results as far as the healing process...Also different people will have other methods that work best for them...I hope this will get you started toward dealing with the 'character traits' that make some bonsai unforgettable and others just so-so...I can safely say you will spend a lifetime working with bonsai and still discover new things and new ways of dealing with these 'faults and features' of the trees...I hope others will also share their thoughts on this subject, because we can all learn from the experiences of others...Wishing you a happy tree 'character trait' development...


Regards
Behr



EDIT: This post is based on the questions you asked, however it is sometimes desirable NOT to inhibit the decaying process, and in fact to use techniques to enhance the decay of wood...Traditionally the process of preserving the tree as much as possible is the norm...Traditionally in Japan the trees are worked on with the idea of it being passed on to future generations...To a certain extent I believe we as Western artist also have this in mind when we work on trees, but I don't feel it is as important to our culture as it is to the Asian way of life...In Japan it is 'taboo' to have deadwood on a deciduous tree due to the fact that it does not last long in nature, but we often see these trees with deadwood because it is constantly happening in new areas...With the methods of wood preservation that are available to us there is no reason that deadwood on most broad leafed trees cannot last throughout our lifetime and possibly future generations also...Above all else have fun and make your trees look like real trees...

__________________
As the Master departed the workshop,
he could have sworn he heard some
one saying rather loudly...
"I thought he would never leave"
San Antonio Bonsai Society, Inc.