Monday 22 April is Earth Day! The theme for 2024, ‘planet vs plastic’, is aiming to raise awareness about plastic use worldwide and to ultimately reduce plastic use by 60% by 2050.

In some cases, reducing plastic usage can be as simple as switching to a wooden toothbrush or stopping using drinking straws, however sometimes it is not as easy to find a suitable alternative. Dartmoor Biodiversity Officer Morwenna discusses the use of plastic tree guards in our work, when they are necessary and how they can be substituted:

This can be a difficult balance as over-predation of young trees by deer and rabbits can cause devastation to newly planted areas whilst plastic tree guards will remain in the environment for a long time only very slowly breaking down into micro plastics which can cause irreparable damage to wildlife and ecosystems.

An estimated 200 million plastic tree guards have been used between 1980 and 2020 in the UK, and many of these will have been left in place littering woodlands or thrown into landfill. This is improving, with more plastic-free alternatives and recycling schemes which re-use tree guards, such as the Tubex recycling programme - though even then a lot of the plastic alternatives still need removing and heating to a high temperature in order to decompose.

Additionally, some of the supposed benefits of tree guards are questionable. The microclimate created within a warming tree guard is said to improve growth rate by 25%, although once the trees have grown tall enough to escape the tube, they are too tall with few branches and poor root systems. Also they have not built up at natural resistance to the wind and with their extra height this makes them vulnerable to collapse. The microclimate inside these tubes also benefits grasses and often trees are found wrapped in a mass of overgrown grass and unable to photosynthesise themselves.  

It is possible to plant trees without the use of any guards, it just takes some extra care and good knowledge about the wildlife in the area. 

Green Recovery 

The reason we are planting any trees is because we are currently working on a Green Recovery programme, funded by South West Water. This project is covering Burrator and Venford and aims to improve biodiversity in these catchments.

Our reservoirs and the land surrounding them are a valuable resource for nature with native woodlands, forestry, wetlands, rivers, grasslands, heathlands and more and many of these habitats would benefit from more trees. Wet woodlands, for example, capture more water in the catchment with their roots holding water in small pools as well as in the trees. Wood pasture is a valuable type of treed landscape which benefits both livestock farming and wildlife by providing shelter and fodder.

Therefore for the past year and next year, we are planting some trees across Burrator and Venford. So far, at Venford we have planted around 1,300 trees, replacing the commercial forestry that was planted there before and at Burrator we have planted around 1,300 wet woodland trees and 26 fruit trees in two new orchards. Across these sites we have used different approaches with or without tree guards.



We planted around 1,300 trees at Venford in January with the help of our volunteers and Moor Trees’ volunteers. This planting was split into four sections, two smaller and two larger.

We have experimented with the use of tree guards here, with two sections guarded and the two larger sections unguarded. In all the areas, we have areas of denser planting and areas with looser woodland planting which will help us to identify what works and what doesn’t, which trees get predated and which are left alone.

The majority of trees planted here were hawthorn, so hopefully some protection is given to the hawthorns themselves and trees they are surrounding by putting predators off with their thorns. We will also see whether the guarded trees grow faster, and whether they survive better in the long-term. It may be that the unguarded sections need ‘beating up’ which means to replace the predated trees with new trees. 

Burrator orchards

We have recently planted two new orchards at Burrator with the help of the children from Meavy primary school. In these orchards we have not used any plastic guards but have instead guarded them with cactus guards. This is a type of mesh guard with sharp spikes on the outside to prevent livestock like ponies and cows from rubbing on them or trying to get to the tree. These guards will remain around the trees for at least the first two years of growth, while they establish and begin to bear fruits.

The trees have also been mulched with wood chip which will provide nutrients for the first year, and we will top this up in six months or a year. Cactus guards are really helpful for this type of planting, where there are few trees and they have lots of space between them, however they are not so good for denser planting where hundreds of trees are planted close together. They can also be used to protect saplings which are naturally regenerating, as is being done across Dartmoor in places like Wistman’s Wood. 

Burrator riparian woodland 

In February and March we planted lots of wet woodland species, including white willow, goat willow, alder and downy birch. These species do well where the land is frequently inundated, for example on a floodplain. We have planted trees within 50m of the river and right up to the banks which will allow the river to change its course slightly, due to roots becoming obstacles. Lateral roots among the floodplain will cause water to pool in boggy patches, creating habitats for invertebrates.

In these areas we have used tree guards and stakes to protect the trees during their establishment because the deer population in these areas is unknown and their impact on the trees could therefore be devastating. However, the guards will be difficult to remove once the trees have established as the area is wet, and will probably get wetter with more trees. We have used taller guards in one area and smaller guards in another, so with any predation, we might be able to tell whether the bigger problem is deer or smaller animals such as voles and rabbits.

In future we will also implement a deer management plan to monitor deer at Burrator and understand the impact they might be having. This way we can maintain a healthy number of deer without the use of tree guards.

Burrator future planting 

We have some more plans for planting at Burrator and will try some different techniques to prevent predation of the trees.

Firstly, we will plant 25% more trees than usual and not guard any. This will mean some trees are likely to be predated, but enough are present that some will survive. There is the additional benefit of the naturalistic randomness of this planting style, the planted trees will look natural and not in a grid-like format. This is a proven technique which is more cost effective than buying stakes and guards for all the trees and removes the need to use plastic at all.

A second method will be ‘sabre planting’. This is a technique used in some rocky and rugged landscapes, particularly successful in Wales where sheep farming is common and young trees are often eaten by the sheep. The technique involves plating trees at an angle in a steep-sided valley and between rocks, as they would naturally grow. This protects the young trees from grazing animals, and gives them a chance to grow with some protection afforded by natural features in the landscape.

On Dartmoor, another abundant natural feature is gorse, where trees can be planted in the middle of the gorse bush and will gain enough light to grow through. This means the tree is protected from nibbling ponies and sheep and will eventually cast enough shade on the gorse to prevent it growing.

These experiments may do really well or may cause a huge loss in the trees we plant, but they are worth trying, as these techniques have the potential to improve tree planting across the country, allowing us to reach our planting targets better. They will also cut the need for plastic tree guards and reduce the long term littering of our new woodlands, or filling up of landfills.

If we want to reach the ambitious tree planting targets set out by the government, it is essential that we reduce this plastic use and have natural woodlands flourishing without plastic.