Modifying mammal access to trees
Source: gov.uk (2025-10-30)

Learn about the modification options to prevent mammal access to trees and woodland, including: sensory deterrents, fences, tree shelters, bud protectors and vegetation control.

Physical exclusion from an area

Fencing (permanent, temporary, and electric)

Associated species or groups of species:
- Eurasian beaver (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/eurasian-beaver)
- rabbits and hares (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/rabbits-and-hares)
- deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)
- pigs and wild boar (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/pigs-and-wild-boar)
- livestock and European bison (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/livestock-and-european-bison)
- horses and ponies (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/horses-and-ponies)
Fencing is a traditional management method used to protect trees by preventing animals from accessing the area. There is a wide range of types and specifications of fence available (https://cdn.forestresearch.gov.uk/2006/03/fctg002.pdf). Choose an appropriate fence for your situation or target mammal species.

Permanent fences

These are intended for use over periods exceeding 5 years. This timeframe generally allows trees to mature beyond their most damage-prone stage (usually between 5 and 15 years of age).

Temporary fences

These are required for periods of less than 5 years. They are most often designed to address short-term management problems or to establish seasonal enclosures (for example, for deer, horses and ponies, and domestic livestock).

Electric fences

Usually, but not always, temporary in nature. Electric fences require a higher level of maintenance than other forms of fencing, but they are easy to assemble and dismantle. Their expensive components (such as the charging unit) can be reused.

The choice between using tree guards, or tubes and fencing can depend on the size of the area being protected, as well as other logistical factors. Tree guards and tubes typically maintain a consistent cost per hectare regardless of area size, whereas fencing becomes more cost-effective as the protected area increases. As a result, there is a threshold below which tree tubes or guards are more economical and above which fencing may be preferred.

For smaller woodlands, particularly those under 3 hectares, tree tubes or guards are often the recommended choice, especially in non-commercial woodlands or where deer control is insufficient to prevent damage (https://www.gov.uk/government/publications/tree-protection-the-use-of-tree-shelters-and-guards).

While fencing is generally more suitable for larger areas, it comes with additional considerations such as:
- access rights of way
- potential landscape issues
To reduce visual impact, fencing may need to follow natural contours rather than straight lines, which can increase costs. Additional features like badger gates or deer leaps may also be necessary depending on the context.

Fencing and gates should be effective for managing mammal access while maintaining public access. Once no longer needed, fences should be dismantled and the materials should be either reused or safely disposed of.

Additional information

Best practice guide to planning, assessing, and choosing the appropriate fence design for the target species (https://www.forestresearch.gov.uk/publications/forest-fencing/) from Forest Research.

Fence specifications for individual mammal species (https://cdn.forestresearch.gov.uk/2022/02/lru_bpg12.pdf) from Forest Research.

How to create woodlands that are resilient in the presence of Eurasian beaver (https://www.nature.scot/doc/naturescot-research-report-1368-how-create-woodlands-are-resilient-presence-beaver-castor-fiber#1-2-managing-herbivore-impacts) from NatureScot.

Countryside stewardship grant finder – deer fencing (https://www.gov.uk/countryside-stewardship-grants/deer-fencing-fg9) from Rural Payments Agency and Natural England.

Countryside stewardship grant finder – temporary deer fencing (https://www.gov.uk/countryside-stewardship-grants/temporary-deer-fencing-fg10) from Rural Payments Agency and Natural England.

Dead hedging

Associated species or groups of species: deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)

A dead hedge is a physical barrier made by weaving or stacking cut branches, stems or other woody vegetation between vertical stakes driven into the ground. The materials are often gathered over time from activities such as pruning, clearing or traditional woodland management practices like coppicing.

When constructed from thorny brash, such as hawthorn, blackthorn and holly, a dead hedge can act as a natural and cost-effective structure to protect trees from deer.

To be effective, the dead hedge must meet species-specific minimum height requirements, similar to those for fences, to prevent deer from jumping over it. Regular maintenance, including adding fresh material as the hedge decomposes, is necessary to ensure the dead hedge remains a functional barrier.

As with any barriers, consider public rights of way when placing dead hedging.

Physical exclusion from an individual tree or shoot

Natural physical protection

Associated species or groups of species:
- small rodents (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/small-rodents)
- deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)
- rabbits and hares (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/rabbits-and-hares)
- livestock and European bison (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/livestock-and-european-bison)
Deadwood retained from activities such as felling or thinning can act as a natural physical barrier to protect individual trees, whether planted or naturally regenerated, from browsing. The size of the deadwood must be appropriate for the species present.

Other proposed methods of natural physical protection include:
- packing cut gorse branches around the base of young trees (https://www.nature.scot/sites/default/files/2025-06/naturescot-commissioned-report-558.pdf)
- direct seeding of valued trees into clusters of established thorny shrubs and trees (sometimes referred to as associational resistance) (https://www.academia.edu/xx-xxxx-xxxx/Shrubs_protect_oak_seedlings_against_ungulate_browsing_in_temperate_broadleaved_forests_of_conservation_interest_A_field_experiment)
However, the effectiveness of these methods remains unclear.

Additional information

Methods for establishing trees without fences in Scotland (https://www.nature.scot/sites/default/files/2025-06/naturescot-commissioned-report-558.pdf) from NatureScot.

Tree shelters, spirals, guards, and tubes

Associated species or groups of species:
- Eurasian beaver (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/eurasian-beaver)
- small rodents (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/small-rodents)
- rabbits and hares (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/rabbits-and-hares)
- deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)
- livestock and European bison (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/livestock-and-european-bison)
Tree shelters, spirals, guards, and tubes are protective structures placed around young or vulnerable trees to physically protect them from being browsed, gnawed, or bark stripped by various mammals.

Tall and medium structures (up to 2 metres high) are primarily designed to protect trees from deer and livestock, while shorter structures are intended to deter smaller animals, such as voles, rabbits and hares.

To effectively protect the tree, the height of the protective structure should be tailored to the size of the species. For example, where there is a high risk of browsing damage, the top of the protective structure should be just above the maximum browse height of the target animal.

Spiral guards are particularly effective against voles and other small rodents, and they are recommended by the Forestry Commission (https://www.gov.uk/government/publications/tree-protection-the-use-of-tree-shelters-and-guards) in all cases when shelters, tubes or guards are not already in use. Spiral guards should be pushed into the ground by about 5mm (https://www.trees.org.uk/Trees.org.uk/files/65/65eccbc9-d15b-463c-807f-58b6be0c5020.pdf) to prevent voles from gaining access to the tree beneath them.

Tree shelters and tubes, typically made from translucent polypropylene, are usually attached to wooden stakes and should provide support and protection for between 5 and 10 years after planting before the material begins to break down. In contrast, tree spirals and guards are typically made from metal or plastic mesh and are wrapped around the tree’s stem.

To protect against Eurasian beavers, stronger welded-mesh guards are required.

While these structures are generally beneficial, they can present challenges in certain conditions:
- in exposed locations with high winds, shelters and tubes may increase the risk of wind snap
- while tree shelters and tubes create a warm, humid microclimate that can promote early growth in some species, others may struggle to survive within these enclosed environments
Efforts are currently underway in the UK to reduce the environmental impact of protective tree structures (https://treecouncil.org.uk/wp-content/uploads/2021/11/7.-PROTECTING-YOUNG-TREES-best-choice-for-your-planting-project-Setember-2021_v8.pdf) by replacing non-biodegradable materials with alternatives, such as:
- paper
- cardboard
- plant starch
- wool
However, their effectiveness is not yet known. If plastic protective structures are used, you must collect them after use and recycle them. Otherwise, they may degrade into smaller plastic pieces that can contaminate the soil and eventually waterways.

Additional information

Protecting trees from Eurasian beavers using wire mesh (https://www.nature.scot/doc/protecting-trees-beavers-using-wire-mesh) from NatureScot.

How to create woodlands that are resilient in the presence of Eurasian beaver (https://www.nature.scot/doc/naturescot-research-report-1368-how-create-woodlands-are-resilient-presence-beaver-castor-fiber#1-2-managing-herbivore-impacts) from NatureScot.

Research into plastic-free tree guards (https://www.woodlandtrust.org.uk/about-us/what-we-do/research-and-evidence/plastic-tree-guards/) from the Woodland Trust.

Tree protection: the use of tree guards and shelters in woodland creation (https://www.gov.uk/government/publications/tree-protection-the-use-of-tree-shelters-and-guards) from the Forestry Commission.

Plastic-fee woodlands impact report (https://www.ydmt.org/resources/images/news/EOCA%20Impact%20Reportv2.pdf) from the Yorkshire Dales Millennium Trust.

Parkland tree guards

Associated species or groups of species
- deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)
- livestock and European bison (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/livestock-and-european-bison)
Parkland tree guards are freestanding enclosures designed to protect individual trees, particularly in wood pasture or parkland habitats where livestock and deer are present. Typically constructed from heavy-duty wooden frames with mesh panelling (though some are made of ironwork), these guards are designed to enclose the tree at a sufficient height and width to prevent browsing, rubbing and other forms of physical damage.

In addition to above-ground protection, parkland tree guards can also help protect a tree’s root system – especially in areas with high mammal populations, where soil compaction and root damage from trampling pose a significant risk to tree survival.

Unlike tree shelters, spirals, guards or tubes, which are commonly intended for young saplings, parkland tree guards provide long-term protection for semi-mature and mature trees.

Bud protectors

Associated species or groups of species: deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)

Bud protectors are designed to protect buds from deer browsing. These protective covers move, or can be adjusted, as the bud grows, providing continuous protection, especially for the leader shoot.

Bud protectors can be made from a variety of materials, including:
- paper
- foil
- netting
- plastic
Mesh bud protectors are available, made from materials that naturally degrade over time. These biodegradable bud protectors allow the bud to grow freely in the following season once the shoot is out of reach of deer and no longer requires protection.

While bud protectors show promise, they have not yet been widely tested in the UK.

Canvas sacking

Associated species or groups of species: Eurasian beaver (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/eurasian-beaver)

Wrapping canvas sacking around the base of a tree, up to 1 metre high, creates a physical barrier that can effectively deter Eurasian beavers from felling the tree (https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2907.1995.tb00443.x) by making it more difficult for them to gnaw through.

Sensory deterrents

Seed coating

Associated species or groups of species: small rodents (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/small-rodents)

There is some evidence that using microencapsulated capsaicin (a substance derived from chilli peppers) to coat seeds can mitigate predation from small rodents.

Acoustic deterrents

Associated species or groups of species: deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)

A 2018 study (https://www.jstage.jst.go.jp/article/rtriqr/59/3/59_207/_pdf) found that deterrent sounds, such as deer alarm calls and dog barking, were effective in keeping deer away from train tracks in Japan, where collisions between deer and trains are a significant problem.

Additional information

LNER celebrates remarkable innovation award win for deer deterrent system (https://www.lner.co.uk/news/lner-celebrates-remarkable-innovation-award-win-for-deer-deterrent-system/).

Sheep’s wool and lanolin-based products

Associated species or groups of species: deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)

Wrapping raw sheep’s wool around the stems and buds of young trees can help protect them from deer browsing damage by acting as a natural repellent.

Alternatively, consider repeated application of lanolin-based sprays such as Trico® (https://ecotree.green/en/blog/how-to-protect-trees-with-trico-a-natural-animal-repellent).

Additional information

Trial of the use of sheep’s wool as an environmentally friendly method for protecting trees from browsing damage caused by deer, as well as other browsers like rabbits and voles (https://www.ydrt.org.uk/wool-tree-protection-trials/) from Yorkshire Dales Rivers Trust.

Deer repellent Trico®: a 2-year review (Forestry & Timber News) (https://prosprayers.co.uk/wp-content/uploads/2023/05/Trico-Review.pdf).

Flashing lights

Associated species or groups of species:
- Eurasian beaver (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/eurasian-beaver)
- deer (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/deer)
Guidance by NatureScot (https://www.nature.scot/sites/default/files/2023-11/BEavers%20in%20Scotland%20SEA%20Environmentla%20Report%20-%20May%202017.pdf), Natural England (https://www.gov.uk/guidance/beavers-how-to-manage-them-and-when-you-need-a-licence) and Defra (https://www.gov.uk/guidance/beavers-how-to-manage-them-and-when-you-need-a-licence) suggest the use of bright flashing lights as a scarer to discourage the unwanted dam-building activities of Eurasian beavers. Similar methods have also been proposed as an effective deterrent for deer.

Before installing flashing lights, check the area for other species that might be negatively affected, especially protected species such as bats. Also consider the effects of light pollution on the surrounding landscape.

Flashing lights should only be used for a short period, as animals can quickly become habituated to them. Remove the lights as soon as the lights become ineffective.

Virtual fences

Associated species or groups of species: livestock and European bison (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/livestock-and-european-bison)

Virtual fencing is an innovative system developed by the Norwegian company Nofence (https://www.nofence.no/en/), whereby a grazing animal wears a GPS-enabled collar that emits an audible warning when the animal approaches an invisible fence boundary. If the animal reaches or crosses the boundary, the collar delivers a mild electric pulse, similar to that of a standard electric fence, to discourage it from straying further.

A grazing area or pasture is mapped using an app, which then communicates with the collar worn by the animal.

Virtual fences allow livestock to safely roam across vast areas – potentially covering hundreds of hectares – without the need for traditional fences or barbed wire. However, before implementing virtual fencing, a training period is essential to help livestock become familiar with the system and learn appropriate behavioural responses.

Additional information

An independent report, published in 2022, on the welfare implications of using virtual fences to contain, move, and monitor domestic cattle, sheep, and goats (https://www.gov.uk/government/publications/awc-opinion-on-the-welfare-implications-of-using-virtual-fencing-for-livestock/opinion-on-the-welfare-implications-of-using-virtual-fencing-systems-to-contain-move-and-monitor-livestock#introduction) from Farm Animal Welfare Committee (FAWC).

Trial of the use of virtual fencing systems to manage cattle grazing intensity (https://forestryandland.gov.scot/news-releases/satellites-control-where-cows-graze-to-promote-biodiversity) in Scotland from Forestry and Land Scotland (FLS).

Trial of the use of virtual fencing systems to manage cattle grazing intensity in Northern Ireland (https://www.cafre.ac.uk/business-support/agriculture/environment/environment-technical-support/virtual-fencing-to-assist-conservation-grazing/) from College of Agriculture, Food, and Rural Affairs (CAFRE).

Vegetation management deterrents

Vegetation control to reduce cover

Associated species or groups of species
- small rodents (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/small-rodents)
- rabbits and hares (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/rabbits-and-hares)
The traditional use of herbicides to reduce competition from vegetation and support tree establishment may also indirectly protect trees from damage caused by small rodents – particularly bank voles, which prefer dense understorey cover – by making the surrounding habitat less suitable for these animals. While herbicide use has been successful in mitigating damage from rabbits and hares globally, evidence of its effectiveness in the UK is limited (https://academic.oup.com/forestry/article-abstract/65/3/281/581424?login=false).

Herbicide application methods vary, including:
- spraying the entire area before or after planting in winter
- targeting only the areas where trees are planted
- applying herbicides within a 1–metre diameter around each individual tree (https://www.gov.uk/government/publications/tree-protection-the-use-of-tree-shelters-and-guards)
Using tree shelters or tubes can increase the speed and efficiency of herbicide application (https://cdn.forestresearch.gov.uk/2004/11/fcrp006.pdf) by minimising the risk of the herbicide contact with the trees.

However, herbicides can have unintended negative impacts on both target and non-target vegetation. In some planting scenarios, such as when establishing scattered trees in wood-pasture areas or above the moorland line, the vegetation being suppressed could hold value in its own right. Chemical applications may degrade important plant species and disrupt local ecosystems.

The UK Forestry Standard guidelines recommend minimising the use of herbicides and fertilisers. Alternative, herbicide-free methods for vegetation control that may be effective in reducing cover for small rodents include:
- mowing (or scarification) (https://cdn.forestresearch.gov.uk/2022/02/lru_bpg11.pdf)
- domestic livestock grazing (https://www.forestresearch.gov.uk/publications/archive-domestic-stock-grazing-to-enhance-woodland-biodiversity/)
- applying mulch (or mulch mats) around the base of individual trees (https://cdn.forestresearch.gov.uk/2022/02/stokes_2012_qjf_mulches_zdklgwc.pdf)
Mown vegetation may still compete with trees for essential nutrients, and there is some evidence that mulch mats may simply provide shelter for voles (https://cdn.forestresearch.gov.uk/2004/11/fcrp006.pdf).

Additional information

Review of available herbicides (and insecticides) for use in forest and woodlands in the United Kingdom (https://www.confor.org.uk/media/247718/ftn-pesticides-review-for-2019.pdf) from CONFOR.

Best practice guidance for weed control for land regeneration (https://cdn.forestresearch.gov.uk/2022/02/lru_bpg11.pdf) from Forest Research.

Integrated forest vegetation management (https://www.forestresearch.gov.uk/research/integrated-forest-vegetation-management/) from Forest Research.

Approaches to sustainable forestry and minimising the use of herbicides (https://assets.publishing.service.gov.uk/media/651670336a423b0014f4c5c0/Revised_UK_Forestry_Standard_-_effective_October_2024.pdf) from the UK Forestry Standard.