by John Boyce | Jul 19th, 07Cutting Bonsai
by John Boyce
Often we find that we must cut into a tree. Sounds simple, doesn’t it? Well, actually it is simple, but the way we do it is another thing altogether.
When you cut off a small twig or branch, get in the habit of cutting it so that the cut faces up and slightly to the back. This will help heal the cut when it faces the sun, will help prevent disease from entering the wound, and because it faces the back it won’t show as much, or not at all.
If it is a larger cut then you should also seal the cut with cut paste. It is always important to use sharp tools when you cut anything on the tree. You want to have a clean wound. This means a sharp cut with no jagged edges. Jagged edges do not heal smoothly, and may not heal at all. If there is any doubt on larger cuts, use a wood chisel to make sure the cambium ring is clean and cut slightly concave. This will ensure a smooth heal over.
If you should find a cut that will not heal over, or an old poorly done cut, clean out the dead wood and scrape the cambium layer to expose a green ring. This will activate the cambium to start growing again and heal over the cut.
Sometimes we must clean out quite a bit of dead wood, and this leaves a deep depression. Be sure to remove all the dead or rotten wood before you seal. Fill the depression with water putty to just below the cambium ring. Let this dry well and then activate the cambium ring again. Make sure the filler is smoothed over the wound so it will look good. If it is a deciduous tree you are working on and the dead wood is not cleaned out, the rot will continue down through the tree. This can result in a wonderful hollow trunk (very seldom) or an ex-bonsai (almost always).
Treat roots the same way. With roots, make the cut so that it faces down, the way roots grow. And again, use sharp cutters. Jagged cuts below the soil line are worse than ones above the soil, due to bacteria and moist conditions. Don’t make bacteria happy; make the roots happy with a clean cut. Here too, on large cuts it does not hurt to use cut paste.
When moss is allowed to grow on roots that are exposed, remove the moss or you can kiss the root goodbye. If part of the root surface is dead, use lime sulfur on it so it does not continue to rot and go into the tree. If that happens you can have a wonderful hollow trunk or, most likely, another ex-bonsai.
(April 1998)
Tags: John Boyce, Tree Care