Injury to Trees From Grazing Animals

Publication Year

2025

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Grazing animals can cause extensive damage to trees, both young and old. Seedlings are removed and mature trees chewed and rubbed against causing severe stress or even death to the tree. Livestock can also erode and compact the surrounding soil which may contribute to the declining health of a tree. Any healthy tree in a landscape or tree nursery can be susceptible to destruction of the cambium tissues. Damage is characterized by vertical scrapes and shredded bark on saplings, exposing underlying wood often having the xylem, phloem, and cambium tissues removed. If the injury has happened recently—less than two weeks—the tree can still have a healthy appearance depending on how much of the tree is injured, the time of year, and the ambient air temperature. The only visual injury at this time is the wound on the surface of the trunk. The amount of injury can determine if the plant lives or dies. If the injury is only on one side of the management practices can be used to minimize impact on trees. Permanent Fencing Mature trees need protection from ringbarking (damaging xylem/phloem), leaf grazing, bunting and rubbing. Without protection, young trees may be completely removed by grazing animals. Permanent fencing around young trees can be constructed so that it will continue to provide protection once the tree matures. Permanent fencing can also be erected around mature trees. A permanent fence can be erected around a single tree, an area of trees or a line of trees. Avoid rough edges that may injure stock, and do not use barbed wire if the paddock is for horses. If electric fencing is already being used on the farm, it is easy to add an additional fence around trees. Treeshelters and Treeguards Treeshelters are tubes of plastic used to provide protection for individual trees and promote the rapid growth of young trees because of the favorable microclimate they provide. Treeguards are usually made from plastic mesh of many different designs. Most larger treeshelters/guards are supported by wooden stakes, but some smaller guards can be supported by the tree they are protecting (such as spiral guards) or by themselves which are simply pushed into the ground. Advantages of treeshelters/guards:

• Cost effective for small areas
• Can make the application of herbicide easier
• Young trees are easier to locate for maintenance when undergrowth becomes tall
• Not a barrier to public access and only one tree at a time is vulnerable to vandals
• Do not prevent positive herbivore impacts on ground vegetation

Disadvantages of treeshelters/guards:

• Do not protect other flora/fauna as does fencing
• Costly for large areas
• Need regular inspection and maintenance
• Usually need to be removed and are generally not re-usable
• Can be an obvious target for vandals

Deer control methods also include odor repellents such as predator urine to treat the area, contact repellents to make plants distasteful, ultrasonic repellents and other scare devices, water spraying devices activated by a motion sensor, strobe lights and noise making devices, dogs inside visible or invisible fences, perimeter fences and meshes 8-10 feet tall, electric fences and meshes, baited electric fences and meshes, and electric deer shocking devices. Most of these deer control methods are ineffective or are effective for only a short time until deer adapt to them. Many deer, especially whitetail, are smart enough and adaptable enough to quickly figure out that these things will not harm them. A strategy for reducing the damage to your trees might include different methods at different times of the year.