Tree guards for forestry and nurseries: deer, rabbit and bark protection

Identify the animal and the injury

Browsing is selective feeding on the buds, shoots and foliage of trees. Bark stripping is usually gnawing or rubbing of the bark, and it can kill a young tree outright if bark is removed in a band around the stem.

Deer and sheep leave a ragged edge on browsed shoots; rabbits and hares make a clean, angled cut.

Before you call the forester or buy anything, photograph the whole affected tree and then the damaged part close up, with a ruler beside it. Note whether shoots were eaten, bark was gnawed, the stem was rubbed or the plant was pushed over, and how high above the ground the damage sits. Height, tooth marks and the time of year help tell browsing from bark stripping.

Look beyond the one tree that catches the eye. Walk the planting and note how far the damage spreads, whether neighbouring species are hit, and whether you can see tracks, droppings, burrows or wool. Write down what you saw separately from your guess at the animal, and send the photos to your forester for identification.

For bark loss all the way round the stem, ask the forester whether the tree is still viable.

Compare tree protectors and fencing

Cost is only one consideration in the choice of plant protection. The others are the visual intrusion of shelters and guards, the restrictions on public access that fences impose, the heightened risk of vandalism on new structures and the desire for faster growth with tree shelters.

Before planting, planning establishes which mammal species and stock are likely to cause damage, present now or likely to invade soon after.

Individual protection costs rise with the number of trees planted; fencing costs relate to the size and shape of the area enclosed.

Draw a simple plan of the site with the tree groups, boundaries, gates, watercourses and the routes you use to reach the trees. Take it to the forester and ask which protection fits the whole site, not which product is cheaper to buy. For a compact block, compare the length of perimeter you would fence with the number of individual guards you would fit. For a scattered planting, decide how you will find and revisit every protected stem. Count inspection during establishment and later removal into the cost of guards and of fencing alike.

Guards are cost effective for small areas. They can protect trees from herbicide damage, make trees easier to locate, leave public access open and give an early boost to growth. They do not protect other woodland vegetation, they are costly for large areas, and tall ones can attract vandalism.

Fencing protects natural regeneration and other woodland vegetation and is often less visually intrusive than individual guards. It is expensive for small areas and reduces access for woodland users. A breach can put the whole planted area at risk, and some reduction of animal numbers may also be needed when populations are high.

Chemical repellents are a useful emergency measure for immediate and over-winter protection of small areas, but they give limited duration of protection and do not protect growth after treatment. Electric fencing has a low capital cost and is reusable, yet it is generally reliable for domestic stock only and fails entirely if power or earthing is lost.

Also ask about the site itself: a sloping edge, an exposed ridge, a wet hollow, a roadside boundary and a path walkers use all need different answers. Mention nearby livestock, woodland, hedgerows and obvious animal paths. For steel mesh, plastic tubes or other materials, ask who supplies spares and how long the product is expected to last, and read installation warranties separately from claims about the material.

Guard height by animal

Voles need split plastic tubes 200 mm tall, buried at least 5 mm into the soil; plastic guards with aeration holes are ineffective against them. Rabbits need 0.6 m tree shelters, split tubes, plastic mesh or spiral guards, though lateral growth may still be browsed with spirals and meshes. Hares need 0.75 m shelters or mesh guards. Roe and muntjac deer need 1.2 m shelters or mesh guards. Sheep need guards 1.8 m tall with two tall stout stakes for most breeds.

Roe deer browse up to 1.1 m and fray bark up to 1.2 m on trees up to about 8 to 10 years old, and muntjac browse and fray up to 1 m. Rabbits ringbark the bottom 50 cm of a stem, and hare damage reaches 70 cm.

Fencing can be an expensive option and may only become cost effective above a certain block size, because the cost per hectare falls considerably on larger areas. Badgers push under and through many lighter meshes, so rabbit netting takes heavy wooden badger gates where their traditional runways occur. In areas where vandalism is likely, tree shelters are ill advised.

Tree trunk protectors: which animals they stop

Tree guards are listed as an option against field voles, bank voles, rabbits, hares and deer, and are not listed against cattle and ponies. For grey squirrels guards are not listed, but isolated specimen trees can have smooth collars fitted.

Against rabbits the guard types are split plastic tubes, plastic mesh and spiral guards; against hares and deer, tree shelters and plastic mesh guards (heights under “Guard height by animal”).

Tell the supplier the species, the size of the stock and how the area will be managed, and say whether it is a forest plantation, a nursery line, an orchard, a hedge or a single landscape tree. Say whether mowing, machinery, livestock or public access will be close by. Ask how the protector copes with branching and a thickening stem, get fitting instructions for the exact product and size, and ask when to check the fit. A photo of a guard on a thin sapling does not show how it behaves as the tree grows. If the delivered stock differs from what you ordered, check the fit on a few trees before fitting the whole batch.

Make wind exposure a design input

Taller guards can be unstable and cause damage to trees and stem weakness in windy situations.

Tell the supplier how exposed the site is, how sheltered it is and what the ground is like, and ask them to explain the stake, the fastening and how they will install it. Plan to look at the guards after stormy weather. If a guard leans, rubs the tree or has come loose, write it down and ask the forester for the cause and the remedy; do not add extra tight ties around the stem.

Keep stakes and shelters secure and upright

Deer tree shelters need on-going maintenance so that stakes and shelters stay secure and upright, and adequate weed control until the trees are established.

Ask the installer to show on one tree how the fastening works and how to check it, and photograph that finished example for your site file. Keep the maker's part names so replacements match. When something fails, work out whether it is the stake, the connector, the shelter wall or the tree, note the state of the tree before repairing, and look for the same failure elsewhere in the planting.

Include the ground around each guard in your inspections. Note competing vegetation and debris, and agree with the contractor which tasks are theirs and which stay with you. If you plan to spray around guards, tell the adviser the tree species and the product and check its label for the site; the Irish register shows formulation and permitted use. Record mowing, hand clearing and spraying separately, so that later damage can be told apart from browsing.

When you inspect, look at the tree as well as the outside of the guard: contact with the stem, branching, deformation, trapped material, stability. Give each problem a location (row, compartment, tree number) and take a wide shot of the surroundings plus a close shot of the defect. Write down repairs and the date of the next check. If the same thing fails repeatedly, give the supplier the product batch and installation details and ask whether the fix changes what you should order next time.

Irish fencing standards

All fencing materials, including posts and wire, must meet the standards required by the Forest Service (DAFM) for a scheme-supported forest.

All grant-aided forests must be fully protected from the time of planting, and fencing grants apply only where there is a genuine need, for example where hedgerows are not tall or strong enough. Cattle need three strands of barbed wire, with plain wire along public roads. Cattle and sheep need sheep netting with one strand of barbed wire. Rabbits and hares need rabbit netting with two strands of barbed wire, and three strands where cattle are also present. Deer need rectangular wire mesh 1.9 m high, or two lengths of sheep wire one over the other, with no barbed wire along the top.

Fencing must meet Irish Standard 436:2007 to claim the higher rates of grant aid. The standard aims at a service life of 15 years where timber posts are in contact with the ground and covers permitted timber species, post sizes, preservatives, pre-treatment drying and labelling. Adequate access to the plantation for management is provided with stiles or secured temporary openings.

Before fencing changes the site, mark the routes used by maintenance crews, harvesting machines, neighbours and any visitors, and agree gate positions with the designer. Note the places where an obstruction would get in the way of inspection or vegetation control. Write down any agreement with a neighbour or contractor separately from the animal-protection plan.

Agroforestry plots must be fenced with appropriate stock-proof fencing, and plants need tree shelters for the first 6 to 8 years, replaced afterwards with plastic geotextile mesh.

Deer tree shelter grant: limits and conditions

The deer tree shelter (DTS) grant in pure broadleaf plots is up to €1,600/ha, to a maximum area of 5 hectares, and alder is not eligible. Minimum stocking is 625 trees/ha, planted at 4 x 4 metres. In conifer plots (FT 10 to 12) the shelters can be used on the 20% additional broadleaf area, with a maximum grant of €625/ha. The lower rate reflects the smaller treated area: 20% of the 625 stems per hectare equates to 125 broadleaf trees.

In an existing forest the same standards apply, but damage levels must be greater than 40% to be eligible. Payment is made when 60% or more of the broadleaf trees, evenly dispersed over the site, are free growing and free from deer damage.

Deer fencing is a second option. It is available for broadleaf forests where deer damage exceeds 40% before the second instalment payment, and deer tree shelters should be considered first. Hare fencing pays €4/m up to a maximum of €640/ha where hare damage exceeds 30%. Forests cannot enter either scheme after the second instalment grant.

Removal of shelters

Shelters break down over time and need to be removed to prevent littering.

Before you accept a quote, ask how the product is meant to be removed, who does the work and how the material will be collected and disposed of. If a supplier promises to take shelters back, ask for that in writing. For products sold as biodegradable, ask for the actual material specification and for evidence that it breaks down in your conditions, and keep a sales label separate from an agreed commitment. Settle who collects failed or displaced pieces.

Protect new trees, seedlings and young trees from deer, beaver and other animals

Protecting newly planted trees, young trees, small trees and seedlings from deer starts with the animal and the injury. Tree seedling protectors, seedling protectors, tree sleeve protectors, metal tree protectors and metal tree trunk protectors are compared in the tables on this page. Ash tree protection and beaver tree protection are different problems: name the species and the damage to the supplier and ask which guard height and material they recommend for it.

Next step

Give the forester the damage photographs and the planting layout, and record later vegetation work in the field history. Related pages: field crop records, crop covers and frost protection, plant passports and seed treatment.