How To Repair Damaged Tree Bark

Wayne Thousand. Clatterbuck Associate Professor Forestry, Wild fauna & Fisheries University of Tennessee

Tree wounds are common and the causes include: broken branches; impacts, abrasions and scrapes; animal harm; insect assault; fire; etc. Wounds ordinarily break the bark and damage the food and water conducting tissues. Wounds also expose the within of the tree to organisms, primarily bacteria and fungi that may infect and cause discoloration and disuse of the wood. Decay tin effect in structurally weakened tree stems and tin can shorten the life of a tree. Decay cannot exist cured. Withal, proper tree care tin limit the progress of decay in an injured tree. This fact sheet discusses tree responses to wounding and what can be washed after wounding to continue the tree healthy.

Tree Response to Wounding:

Trees respond to wounding or injury in ii ways: compartmentalization and the development of bulwark zones (Shigo 1986).

Compartmentalization

When a tree is wounded, the injured tissue is not repaired and does not heal. Trees do not heal; they seal. If yous wait at an old wound, you volition find that it does not "heal" from the inside out, but eventually the tree covers the opening by forming specialized "callus" tissue around the edges of the wound. Later on wounding, new forest growing around the wound forms a protective boundary preventing the infection or disuse from spreading into the new tissue. Thus, the tree responds to the injury by "compartmentalizing" or isolating the older, injured tissue with the gradual growth of new, healthy tissue.

Barrier Zones

Not just do trees effort to close the damaged tissue from the outside, they also make the existing wood surrounding the wound unsuitable for spread of decay organisms. Although these processes are non well understood, the tree tries to avoid farther injury by setting chemical and physical boundaries around the infected cells, reacting to the pathogen and circumscribed the impairment.

If the tree is fast and effective with its purlieus-setting mechanisms, the infection remains localized and does non spread. Yet, if the boundary-setting mechanisms are not effective, the infection volition spread. Most vigorous or actively growing trees are fairly successful in coping with decay-spreading mechanisms.

Intendance for Tree Wounds:

Proper care of tree wounds encourages callus growth and wound closure.

Concrete Repair

Tree wounds often appear ragged where the bark is torn during the injury. This is mutual during co-operative breakage and when the trunk of the tree has been scraped. To repair this blazon of damage, cut off whatsoever ragged bark edges with a sharp knife. Accept care non to remove any good for you bark and expose more than alive tissue than necessary. If possible, the wound should be shaped like an elongated oval, with the long axis running vertically along the trunk or limb. All bark around the wound should be tight.

Wound Dressings

Research indicates that wound dressings (materials such as tar or pigment) do not prevent disuse and may fifty-fifty interfere with wound closure. Wound dressings can have the following detrimental furnishings:

Prevent drying and encourage fungal growth
Interfere with formation of wound wood or callus tissue
Inhibit compartmentalization
Perchance serve as a food source for pathogens

For these reasons, applying wound dressings is not recommended. Trees, similar many organisms, have their own mechanisms to deter the spread of decay organisms, insects and disease.

Cavity Filling

Filling big holes or hollows in the tree is generally done for cosmetic reasons. There is fiddling information to indicate that a filled tree has better mechanical stability. However, fillings may give the callus tissue a place to seat, thus stopping the in-whorl (folding) of the callus (Shigo 1982). Almost any filling can be used equally long as information technology does not abrade the within of the tree.

Filling a tree cavity is generally expensive and not recommended. Filling does not stop decay and often during the cleaning of the crenel, the boundary that separates the sound wood or the callus growth from the rust-covered wood is ruptured. Thus, this cleaning for cavity filling tin have more detrimental effects on the tree than if it were left alone. Care must be taken not to damage the new callus tissue that has formed in response to the tree damage and subsequent disuse.

Pruning Wounds

Proper pruning should be used to remove dead, dying and cleaved branches; to remove low, crossing or chancy branches; and to command the size of the tree. However, pruning of whatever kind places some stress on the tree by removing food-producing leaves (if the branch is alive), creating wounds that require free energy to seal, and providing possible entry points for affliction.

Pruning cuts should exist made to maximize the tree'due south power to close its wound and defend itself from infection. When pruning, brand make clean, shine cuts. Practise not leave branch stubs. Exit a small-scale collar of forest at the base of the branch. The branch collar is a slightly bloated expanse where the co-operative attaches to the trunk. Cut the limb flush with the trunk will leave a larger expanse to callus over and a greater chance of decay organisms inbound the wound. The optimal pruning fourth dimension is in the wintertime (dormant season) when temperatures and infection rates are lower and when trees are not actively growing.

Conclusion. Good for you trees normally recover from wounding quickly. Try to continue wounded copse growing vigorously by watering them during droughts and providing proper fertilization. This will increment the rate of wound closure, enhance callus growth and meliorate the resistance to decay mechanisms.

References

Shigo, A.L. 1982. Tree health. Periodical of Arboriculture 8(12):311-316.

Shigo, A.L. 1986. A New Tree Biology. Shigo Copse & Associates, Durham, NH. 595 p.