Violent winds, as well as the weight of the snow, are usually responsible for breaking branches; but machines, lawnmowers and motor cultivators can also occasionally cause damage to logs. In order to repair such damage in the best possible way, two types of intervention are proposed: the cutting of damaged branches and the possible treatment of injuries.
For the wounds, both accidental and due to pruning, in the past it was suggested to fill all the cuts of the branches over 6 or 7 cm in diameter as an aid to healing, with the so-called mastics or tar-like healing paints.
At present, this type of intervention is no longer recommended, as effects totally opposite to those desired have been observed. The development of fungal or bacterial rot was even increased. Trees do not “heal” their wounds as humans do, but close their wounds to isolate areas with rotting wood.
In order to control the possible development of fungal diseases or bacteria and rodent insect plagues, it is preferable to use bactericidal fungicides or conventional insecticides in wound areas instead of so-called healing paints.
Actually, one of the reasons for using these products is aesthetic, or better still psychological, because the aforementioned application on a wound causes, implicitly, the false recognition that something is being done for the health of the tree. In the case of breakage of main branches at the height of the trunk, in general it is preferable not to touch them and to limit oneself exclusively to eliminating the acute angles of the change that have remained.
In the treatment of wounds of the bark of mechanical origin, which do not affect the gearbox, you can only remove the damaged or detached bark without affecting the living tissue. Once the damage has been identified, it is necessary to intervene promptly to save the gearbox as much as possible. It must be covered with a material that preserves moisture, impregnated with fungicide-bactericide, then wrap it with plastic material, opaque if the wound is exposed to the sun; then tie it to the trunk so that it remains moist for a few weeks, the time needed for the change to begin to regenerate the bark. After this time, the pack must be removed.
It is not recommended to fill the cavities in the trunk, as this can be harmful to the tree. In any case, if you fill a cavity, the filling should be made of non-rigid materials. This should never be done if the scarring callus of the wound is affected.
The scarring callus is very thick and has not developed quickly enough in the wound of this chestnut tree. There is a risk that the cavity will last forever, with the consequent danger of an attack by fungi (these will soften the wood which will break into a thousand pieces and the centre of the tree will empty as in the case of the plane tree next to it).
Injury To The Terminal Bud
It is not difficult to find trees whose terminal bud has a wound, due to an animal or the gardener. If the gardener is not aware of this, he will let the 2 buds below develop, inappropriately. It will form, therefore, a bifurcation with acute angle and 2 rival trunks. At times, one of these prevails, whilst the other one moves away a little from the vertical and, under the effect of its weight, separates from the “dominant” trunk by a fissure. The only possible type of repair is the placement of a ring at the base of each one (but, afterwards, one must pay attention to the fact that no ring strangles its support), which will approach with a screw tensioner, i.e. adjustable, to join the separation of the two trunks.
You need to know how to disinfect the wounds, with Bordeaux pulp concentrated at 3%, preferably during the dry season and when the tree is not damp. Afterwards, it is necessary to fill them up, in order to avoid possible infections by cryptogams, as well as the invasion of birds or insects, or even rainwater. Otherwise, the infection could spread through the crack and create descending, dry or wet rot.