A heightened concern for the planet has created a feverish tree planting drive over the past two years in the United Kingdom. In each of the past two years, The Forestry Commission calculates that nearly four million trees were planted by government-supported organisations alone, 1.5x the planting rate over the four years prior.* This woody boom prompts question about the sale, distribution and recycling of oil-based plastic tree guards, also called "tree shelters." From 20 - 180cm in length, these plastic tubes are now a common sight across the countryside, with zealous landowners, motorway builders and farmers puncturing their properties with saplings, increasing the market tree guards manufacturers.
Short history
Tree guards have been used around the world since 1970s to protect planting from local browsers and harsh weather, while also providing an ambient growing environment for a young tree. Typically made from polyethylene (HDPE) or polypropylene (PP), their durable properties have proved effective in preventing browsers like Roe deer, voles and rabbits from feeding on young trees. Only once leaves and branches reach above grazing height can tree guards be safely removed, usually after 5-7 years.
The fossil-based guards that were introduced over the past forty years have proven effective for protecting trees. As well as being strong and non-brittle, plastic has allowed manufacturers to develop the right translucency for sunlight to stimulate photosynthesis - up to 80% is required. With the help of tree guards, landowners have been able to increase their yield - typically three in four saplings reach maturity when protected. Nylon zip ties are usually needed to fasten tubes to poles to keep the tube in a standing position low against the soil.
The impressive durability of polypropylene tree guards is also their shortcoming, remaining in landscapes after their useful life. When they eventually come loose from the tree, they slowly break down creating microplastic waste and prohibitting the further development of the forest or woodland floor.
Emergent alternatives
Founded in the 1970s, Tubex are a major manufacture of tree guards producing a range of models out of Aberdare, Wales. Their inventory includes a variety of tree guards specifically for vines, shrubs as well as for broadleaf saplings, with forms including wraps, translucent tubes as well as mesh. The "Voleguard" model has one rodent in mind, designed with a robust shell to fend off the determined burrower.
Tubex have introduced a biobased alternative (Tubex Nature), joining a suite of manufacturers that have pioneered non-plastic materials that mitigate the toxic residues and microplastic left by polypropylene. Soil biodegradability is the key goal for the most progressive manufacturers, achieved by Vigilis Tree Shelters who have spent £500,000 researched a tree guard derived from potatoes, wood and corn. Each of the Vigilis and Tubex products are shaped into twin-wall tube to increase strength.
Grown Green have made a cardboard-based tree guard which is yet to prove effective beyond its second year, also failing on translucency. An egg box-like tree guard is making progress with holes to allow sunlight, and a translucent version made of sheep wool and nut resin has been tested by forestry expert Alex MacKinnon.
Other manufacturers have claimed biodegradable versions by using Polylactic acid (PLA) - the same material used for takeaway coffee lids. PLA only composts down at 58 degrees Celsius in industrial composting facilities, so isn't considered a valid introduction. Meanwhile Tree Defender's Pro Shelter Guard uses recycled polypropylene, also part of the Tubex Standard range.
Case studies
The Woodland Trust were responsible for planting nearly 400,000 trees in 2022-23, giving them the opportunity to test the practicality of biodegradable tree guards at scale. At a site east of Bath, Woodland Manager Joe Middleton has been trialling 17 types of non-plastic tree guards to protect 2,500 saplings (half of the site's total, shown in header image). A range of tree species have been planted alongside an ancient wood, including Oak, Wild cherry, Hornbeam, Silver birch, Small-leaved Lime, Wych Elm and Field maple.**
Woodland Trust have also been working with Forest of Avon Trust and Avon Needs Trees south of Bristol on a 100-acre site - Great Avon Wood. There they been using been using three types of alternative guards: the Tubex Nature as well as Rainbow Bio Spiral and Tree Hugger.
Other planting approaches point out the option to only selectively use tree guards at areas most prone to grazing. Tilhill is one of the largest commercial forestry management companies in the UK, planting approximately 15 million trees in 2022. But fewer than 10% of trees are planted with tree guards, which are only used where tree species and the environment require. To control browsers options such as natural lanolin-based deer repellent and fencing can be used successfully. Other measures, such as natural lanolin-based deer repellent and fencing are used - generally deer numbers need to be below seven per 100 hectares to prevent serious overgrazing.
Tilhill manages the 560-hectare Jerah Woodland in Stirlingshire, Scotland where half the 1.2-million planted trees were fixed with smaller spirals and vole-guards to reduce plastic used overall and deer numbers were closely managed to prevent browsing. On average 17 deer per 100 hectares need to culled at Jerah each year (based on the past 10 years). The forestry company are also participating in the Forest Plastics Working Group (FPWG) and supports the five-year research project being steered by Forestry Research in England and Scotland on the performance of alternatives to the plastic tree guard.
Recycling tree guards
The distribution of end-of-life guards in hard-to-reach locations presents an operational speed bump for recycling tree guards in the UK. Added to their remote locations, fully mature trees often swallowing parts of the plastic in their trunks making them difficult to remove in whole. To complicate the washing process, tree guards left out too long begin to gather moss, with those fallen tubes become clumped in soil. But Tubex and other manufacturers have taken steps to build out return schemes, while planters like Tilhill have pledged to endeavour to remove legacy tree guards from all their sites by the end of 2025.
Tubex's recycling hubs present the most comprehensive national approach to returning tree guards using deposit locations. The return flow starts with an elegant Typeform for submitting information about a customer's return needs. After being collected, polypropylene tubes are washed and turned into flake, then pelletised and passed back to Tubex in Wales where pellets can be used for the Tubex Standard product. 40 metric tonnes of tree guards have been recycled since collection started three years ago.
Rainbow have announced a recycling scheme for PVC spirals in partnership with GreenTech, setting a minimum of six bags per collection. In South-West England, Farming and Wildlife Advisory Group (FWAG) SouthWest have introduced a Farm Plastic Recycling Scheme with drop-off days in May.
Agri-cycle operate a general plastic recycling operation across the UK, not only for tree guards but for any type of plastic-based agricultural waste. Cheviot Trees provide advice for lots of recycling schemes for miscellaneous or non-standard tree shelters.
Next chapter for tree guards
As well as switching towards soil biodegradability or fully circular recycling, tree guards need to be taken into consideration along with the wider use of plastic within tree planting. Nicola Abbatt from Tilhill notes a series of ways that plastic is used to support tree planting operations:
- Tree bags which are made of heavy duty plastic and are used to deliver young trees and saplings to woodland sites for planting
- Plastic wrapping that is found around stakes and tubes on delivery.
- Barriers and temporary fencing including silt netting for preventing diffuse pollution is all made from plastic.
- Pesticide containers, oil and fuel containers all found in forestry operations all contain plastic.
- PPE, Spill Kits and First Aid Kits. Signage in forestry both temporary and permanent
The improvement of tree planting to improve the health of trees should also be part of the environmental consideration. Obligated to plant trees on the verges of motorways, contractors often fail to develop mature trees - see A14 between Cambridge and Huntingdon (Sky News). Best practice tree maintenance is needed to ensure trees aren't being overwhelmed by weeds or increasingly stressed by extreme weather.
Footnotes
- * Equivalent of 10,822,000 trees were planted over four years, 2017-2021 (source)
- ** also Beech, Common Whitebeam, Aspen, Wild service tree, Alder, Rowan, Hazel, Hawthorn, Crab apple, Spindle, Holly, Guelder Rose, Dogwood, Wayfaring tree, Dog rose, Buckthorn
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