Evolution of plastic tree guards from plastic sleeves, to tabbed fluted guards to fast-to-install welded guards
Fluted guards offer good protection in harsh environmental conditions. Often they can be re-used and they are 100% recyclable. Ideally guards should always be removed from the site once the plantings have matured.
Tree guards are often required for protecting new plantings. In the context of revegetation, plastic has been widely used due to the material’s longevity and ability to be shaped into various forms suitable for different applications. Protection is primarily required against predation and weather events. On the other hand, with street tree plantings, steel and aluminium guards are essential and commonly used for protection from pedestrian and vehicular damage.
Over time, tree guards have evolved from plastic sleeves to tabbed plastic guards to plastic-welded guards in the Landcare sphere, with a robust and current push toward biodegradable guards due to a greater understanding of the impacts of plastic in our environment.
Contractors, landholders, Landcare groups – or anyone planting a tree – need to consider several factors when installing tree guards. Factors to consider include:
Cost of the tree guard
Essentially, the cheaper the tree guard (and the tree), the more trees you can plant for the equivalent overall budget. Who doesn’t like saving money?
Speed of installation
All planting projects have a labour cost, whether it is a dollar cost to a contractor or a time cost to a volunteer. The faster you can install a tree guard, the lower the overall cost of the project, and the more trees you can put in the ground for the same money.
Lifespan or reusability
The longer a tree guard lasts, the more extended protection is available to the tree. In some cases, a tree guard may even be able to be removed and used for successive seasons, which reduces the overall cost for each project.
Conversely, a longer-lasting tree guard may have a long-term environmental impact if not removed, especially if constructed from a non-biodegradable material.
Appearance or aesthetics
Appearance is more critical with street tree protection, where a tree guard needs to be aesthetically pleasing to suit the street vista. It is still of minor importance in Landcare projects, mainly when the project is in a highly visible area.
Poorly constructed tree guards that easily break and look unkempt detract from the overall appearance of the site and can detract from contractor/landholder reputation.
Recyclable or environmentally-friendly
Where the guard ends up at the end of its lifecycle is a critical factor, especially in Landcare. A fully biodegradable guard can be left onsite to break down, reducing collection and recycling costs. However, a non-recyclable plastic guard will have negative environmental impacts, as it will likely end up in a landfill.
A recyclable plastic guard can be turned back into other products or recycled into another tree guard. One of the exciting evolutions of plastic tree guards commonly used in revegetation projects is the transition from a plastic sleeve to a more rigid ‘tabbed’ guard, to a ‘welded’ guard.
The Mallee BioGuard tube guard offers a similar volume to a fluted (Corflute style) guard. While their lifespan is less they will break-down naturally onsite. Also available in a 2L carton guard, the stock is 100% biodegradable leaving no trace on the environment in the long term.
The plastic sleeve was held in place with three bamboo canes or hardwood stakes and was an extremely cheap tree guard solution. As an affordable option, plastic sleeves are still used in projects with small budgets. The significant downsides are how difficult they are to install and how easily they blow away if the stakes lose their tension. Plastic sleeves are also less easy to recycle, with fewer locations able to recycle the soft plastics from which they are made.
Tabbed guards would come as a flat-packed unit and required the installer to carefully insert different plastic tabs into each other to create a triangular structure. Tabbed guards have a minor advantage in that they can be opened up and placed around larger trees. Still, any tree large enough to require a tabbed guard to be opened up to go around has likely grown to a size sufficient enough to make using a guard pointless – other than spraying around it. The downside is that the time it takes to join all the tabs together and install them is more frustrating than the benefit of being able to open them up around a plant.
A welded guard also comes as a flat-packed unit but can easily be ‘popped’ open to create the triangular structure, saving significant time when installing. This time-saving translates to more trees getting planted for the same amount of money. In addition, the weld is significantly more robust than the tab system, which means a longer-lasting guard that is also reusable, saving further costs. A stronger guard also means less breaking apart onsite, providing a neater, tidier, and more presentable site – and less plastic ending up in the water!
It is clear from walking around planting sites where these tree guards are used that the primary problem with plastic guards, regardless of how they are constructed, is where they end up at the end of their life. Unless a collection program is implemented, the guards slowly fragment into microplastics, end up in our waterways, and may contribute to additional ecological problems. A responsible project manager will ensure the guards are collected and disposed of appropriately or recycled. Unfortunately, this doesn’t always happen.
The next stage of evolution for these guards is to continue to research further options for a fully biodegradable version. Steps have been made in this direction, utilising cardboard as a construction medium. Some of these options have had tremendous success, including the Mallee BioGuard Tube Guard and the Mallee BioGuard 2L Carton Guard. A downside to these is their lifespan compared with a plastic guard – they are typically a single-season guard which breaks down after the first season. While this is a requirement to be considered a compostable product – and works well in many applications – some situations require a guard with a more extended lifespan, which would be beneficial!
Stay tuned as we look into various options for biodegradable plastics, the next stage of evolution for these guards.