Closing large cuts on Maple bonsai
Since some 5 years I have an old Japanese maple. I got it from a nursery specialized in maples. In the corner they had a stack of trees that did not fully survive a late frost that spring (Which is exactly why I went there. The grafted variety had died off. A number of large areas of die-back makes this a less desirable trunk. On the other hand, it provides me with lots of practice in how to get wounds to close, I have been layering and testing the limits of rootwork.
That being said.. I noticed that the large wound on the front had stopped closing. Where this summer I saw other large marks close up to half a cm all around, this one stalled. With a pen knife I explored the deadwood section. It was soft. In other words, even though I added wood hardener to the deadwood of this bonsai to be, it stopped working and the wood started to rot.
Removing rotting wood
Time for my carving tools. For this work I have a small dremel with a few round caring heads. So with this gentle tool I started to carve the soft wood off the top, in an attempt to find the hard, healthy living part of the trunk. What happened next surprised me. As I put the rotary bit on the deadwood, it pretty much exploded. The top mm or so was still together. However, below this the wood was completely eaten by borers. So I spent another 20 minutes or so digging deeper with the dremel, completely cleaning out all deadwood.
Filling the cavity
The next step was mixing some cement. With the cement I filled all the dug out spaces. To the tree, it does not matter whether it covers wood or cement with new wood and bark. So this will be a perfect way of getting the big wound on the front to start closing further. Once the cement is all set, I will cut the edges of the bark around the cement and add cutpaste on top. There are still a few more weeks before winter comes and a lot of sugars will still move around. Let’s hope I can restart the bark growing over the open space. Who knows.. Maybe next year the wound will be nearly closed?