Correcting trunk direction
Posted: December 13th, 2008, 3:27 am
DRASTIC CHANGE OF GROWTH DIRECTION
Taking a wedge of material out of a wrongly aligned branch or trunk is a very dramatic way of redirecting an otherwise stiffly lignified part of a tree.
It is probably much more likely to be successful in inexperienced hands than free grafting procedures because a lifeline of undamaged bark can be left to nourish the site. I did it twice in successive years without killing the subject, which was a Cedrus atlantica glauca that had previously been trained into a question mark shape in my inexperienced earlier years.
If the operation is carried out in the vicinity of a growth bud, that would probably help the flow of nutrients as well although I have no evidence to support this.
Using a very sharp saw with tiny teeth that cuts on the pull stroke, I cut into the site
where the redirection was to take place, on the outside of the undesired bend, stopping
just over three-quarters of the way through . Another cut was made above the first one,
angled down to join up with the deepest part of the first cut. The distance between the
open ends of the two cuts is dependant on the degree of direction change required and I would consider that it does not make much difference to the probable success of the
operation. The open ends of the resultant gap were then closed together and held with a smear of superglue on the heartwood only. The glue must not come into contact with the cambium -the lifelines as it were. I made sure that the cambium layers on each side of the gap came into contact with each other. There must be no further movement between the two sides and I bound a splint made of two pieces of thick wire across the wound, leaving the middle bit open until it had been smeared with Lac Balsam to seal it.
A second pair of hands to hold it together would have been useful but I managed. I have been told that grafting wax would have been the best choice here but I had none and did have the Lac Balsam to hand. The binding [with raffia] was then continued over the entire site in three layers and held in place with a normal spiral wire pattern. This was done at a time when active growth was taking place and was not disturbed, as far as I can remember for something like four months afterwards. With aftersight, I would leave it longer, even for the full year. It was difficult not to look how it was progressing meanwhile but I withstood the temptation because the growth above the sites never seemed to flag.
Taking a wedge of material out of a wrongly aligned branch or trunk is a very dramatic way of redirecting an otherwise stiffly lignified part of a tree.
It is probably much more likely to be successful in inexperienced hands than free grafting procedures because a lifeline of undamaged bark can be left to nourish the site. I did it twice in successive years without killing the subject, which was a Cedrus atlantica glauca that had previously been trained into a question mark shape in my inexperienced earlier years.
If the operation is carried out in the vicinity of a growth bud, that would probably help the flow of nutrients as well although I have no evidence to support this.
Using a very sharp saw with tiny teeth that cuts on the pull stroke, I cut into the site
where the redirection was to take place, on the outside of the undesired bend, stopping
just over three-quarters of the way through . Another cut was made above the first one,
angled down to join up with the deepest part of the first cut. The distance between the
open ends of the two cuts is dependant on the degree of direction change required and I would consider that it does not make much difference to the probable success of the
operation. The open ends of the resultant gap were then closed together and held with a smear of superglue on the heartwood only. The glue must not come into contact with the cambium -the lifelines as it were. I made sure that the cambium layers on each side of the gap came into contact with each other. There must be no further movement between the two sides and I bound a splint made of two pieces of thick wire across the wound, leaving the middle bit open until it had been smeared with Lac Balsam to seal it.
A second pair of hands to hold it together would have been useful but I managed. I have been told that grafting wax would have been the best choice here but I had none and did have the Lac Balsam to hand. The binding [with raffia] was then continued over the entire site in three layers and held in place with a normal spiral wire pattern. This was done at a time when active growth was taking place and was not disturbed, as far as I can remember for something like four months afterwards. With aftersight, I would leave it longer, even for the full year. It was difficult not to look how it was progressing meanwhile but I withstood the temptation because the growth above the sites never seemed to flag.
