Rainbow: Castle Howard project bids to close tree shelter supply loop

CELEBRATING its 60th anniversary this year, Rainbow Professional is a company renowned for its tree-care products, working with foresters across the decades to ensure millions of trees reach maturity.

It was 25 years ago that the firm launched its 100-per-cent recycled Rainbow spiral tree guards and in the last five years it has brought several plant- and bio-based products to market, including the certified soil-biodegradable Rainbow Terra.

However, with plastic guards remaining the best-selling and most reliable way of protecting young trees, it has also worked to develop a new scheme to recover such plastic from the natural environment.

Operating with a range of partners to recycle any old PVC spiral or PVC vole guard, the Rainbow Recycling Scheme is available to any professional end user and aims to be affordable and simple to administer.

Bags can be ordered direct from Rainbow or one of its wholesalers such as Greentech.

Once full, they will be collected and transported to Rainbow’s manufacturing facility in Hull where they will be shredded and washed if needed. Depending on the quality, they may be immediately usable to process into new spirals, processed further into pellets, or used as in-fill for window frames. As Rainbow uses 100-per-cent recycled materials, it has a local network of recycling partners that can find the best possible outlet for each waste material.

While a new launch for 2023, it’s a scheme that has been in development for over two years, and got underway following a request from Francesca Pert, project officer for Howardian Hills AONB.

At 204 km², the Howardian Hills is among the smallest of England’s 34 Areas of Outstanding Natural Beauty (soon to be rebranded ‘National Landscapes’). Nestled between the North York Moors National Park, the Yorkshire Wolds and the Vale of York, it boasts a patchwork of arable and pasture fields, scenic villages and historic country houses and a good deal of well-wooded rolling countryside.

Castle Howard (Image: Supplied)

Much of its woodland was planted using plastic tree guards, which became an important topic of discussion in January 2020, when one of Francesca’s colleagues circulated the proceedings of a Yorkshire Dales Millennium Trust workshop entitled ‘Plastic Tree Tubes, Who Needs Them?’.

“The report impassioned me because I knew that what we did for the good of the environment (i.e. facilitate the planting of trees and hedgerows) was contributing to the growing plastic pollution problem,” she said. “COVID actually helped on this occasion because lockdown curtailed some of our other work, so I had some time to look into what the issues in our local area were. 

“Looking back through our records I learned that, since 2008, the Howardian Hills partnership grant aided the planting of nearly 11,000 metres of biodiverse hedgerow.

These provide impressive improvements to habitat connectivity, biodiversity and landscape aesthetics, of which we should be very proud, but at what cost? Our team felt we owned some responsibility for the plastic tree protection which enters the environment (a part share also rests on landowners, plant nurseries and product manufacturers).

“I contacted Castle Howard tree nursery as I knew they supplied many of our grant recipients with their plants and sundries. They passed on Rainbow Professional’s details and that is when I got in touch.”

It was in November 2020 that Francesca reached out to Rainbow regarding the removal and recycling of spirals. Looking at the issues around removing tree shelters, she had already identified two main blockers for landowners: the labour to remove and disposal of the waste generated.

She said: “It made sense to me to look for solutions to these issues before attempting to persuade landowners to remove their spirals. On speaking to Pierre and Alex from Rainbow I could tell that we could work towards a common goal.

“Rainbow Professional’s base in Hull is relatively local to the Howardian Hills, so I proposed we trial removing some spirals to test the practicalities of removal and to provide Rainbow with material to perform recycling tests back at the factory.”

In April 2021 Rainbow joined a team from the Howardian Hills, Castle Howard Estate and the Local Nature Partnership (which circulated the report that sparked the work) to remove 600 PVC spirals. 

Guy Thallon, head of natural environment at Castle Howard, explained why it was so important for the estate to get involved with the trial.

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“The responsible stewardship of the natural environment has always been a priority for Castle Howard Estate, most recently reflected in the ‘regenerate pillar’ of the estate’s long-term strategy, which identifies the important role the natural environment has to play to supporting an estate and its associated communities,” he said. 

“By protecting and enhancing the natural environment, we are able to rebuild ecological systems and process and protect biodiversity, sequester carbon and manage the land for future generations.”  

Plastics waste from already 100-per-cent-recycled spirals is extensive across the estate, he explained. “We have more the 50 km of hedgerows across our land and although many of these are wide, mature and long-standing heritage features, we also have significant stretches of modern hedgerows planted over the last 50 years where plastic spirals have been the most common practice for the protection of young plants.

“We also have an estate tree nursery were a significant proportion of the trees we sell are hedgerow plants, so our decisions and practices can help improve our own environment as well as those who buy trees from us.”

Through long-term collaboration with the Howardian Hills AONB and Rainbow, Castle Howard has been working to support the transition. The recycling of spirals and guards already extant in the natural environment is a key area of activity.

All parties agree hedgerow spirals are needed to give a hedge the best chance of success, protecting it from damage and predation. At the same time, transitioning to a norm of 100-per-cent recycled or biodegradable guards should be a priority for all involved.

Explaining what had lessons had been learned from being involved in the scheme to date, Guy said: “We are proud to have been part of a collaboration that has worked to understand the practical steps required to collect spirals from maturing hedgerow and the expert processing to recover usable materials. 

“Hedgerows need spirals for the first few years of their life before they outgrow the spirals they had when they were first planted. Rainbow plastic spirals are already 100-per-cent recycled when installed and as all plastics do, they deteriorate with UV exposure so the timing of collection is important to catch the spirals when they are still flexible enough to come away from the trees in one piece, speeding up collection and minimising any shards that may remain under the hedge.

“Timing in the year is also important both to gain access the understorey of the hedge and also to collect at a time before, or long after, the hedge has been cut, reducing the risk to the collector of sharp branches or thorns from recent cutting.

"Mass events are best, as individually the progress can be demotivatingly slow. In a day, a team of 20 can clear spirals from a few hundred metres of hedgerow, which is a visible contribution to the full length of the hedge and landscape.

“Lastly, collaboration is key, working with organisations that have shared values and enabling each to identify areas to work on and subsequently address, ultimately building the business case for these organisations to work together over the long term to see change happen.”

Steve Wiles, a toolmaker at Rainbow Professional, has been heavily involved in the development of a recycling scheme through the trials. Given that Rainbow’s spirals are already produced from 100-per-cent recycled plastic, the idea of recycling them again required careful consideration.

He said: “In essence, manufacturing a virgin product is about achieving maximum efficiency. There is no noise in your production process, and you can tailor and streamline everything around the raw material. Consistency is constant. The opposite holds for a recyclate or waste, where variability is the only constant. The secret lies in learning how to manage that variability and adapt the machinery and build a resilient team that is passionate to work around these challenges. This experience also makes us well positioned to make this recycling operation a success. 

“Secondly, as we deal with post-consumer waste here, washing and sorting are the first important steps to undertake to understand the quality of the used spirals. We analyse properties and degradation caused by age and colour. This allows us to segment the plastics into different qualities and decide about end-use possibilities.”

It is possible to make different types of products from the third-generation recyclate, depending on the defined quality of the used spirals. Rainbow Professional has already identified and tested several options.

“Most of the waste will be of reasonable quality and will be used to make our tree ties, a product that we have been making since the 1960s,” said Steve. “The main operation of a tree tie is to withstand high winds and thus we test on tensile strength and look at the elongation at break.

“As we do not always have the same consistency of wind, we also want the tree tie to have memory (going back into its original state) and some elasticity in order to go with the tree and not against it by being rigid. These qualities are tested empirically with a weight system. As a rule of thumb, we allow about 10–15 per cent of third-generation waste.

“If the product is too brittle for the use of tree ties, we will send it over to pipe and window manufactures. They tend to use this type of PVC as a filling layer. Lastly, if the product has incurred contamination we have a last resort which is to turn the plastics into energy, to avoid any of them ending up in landfill.”

Since April 2021 Rainbow Professional has clearly been working hard on both developing a recycling scheme and developing alternatives to PVC spirals. The Howardian Hills has been encouraging hedge-planting grant recipients to use alternative protective products such as the Rainbow Bio 2 spirals (PLA or corn-based spirals). Of course, these are more expensive when only considering the up-front costs, and that deters people. It is crucial that landowners factor in the financial and environmental costs of removal and recycling (or not) at the very start of their planting plans. Having healthy hedgerows but soil and water full of shattered shards of PVC makes no sense.

In an effort to prevent more PVC entering the landscape, the HHAONB team have been including an offer to pay the difference between standard plastic spirals and bio-compostable ones when talking to grant recipients. Unfortunately, the most convenient supplier for hedging plants may not also stock alternative spiral guards, so this has not been as simple as hoped.

Following the initial trial, Francesca wrote up recommendations for removal, including practicalities and health and safety considerations. On completion, she presented the progress to the Forest Plastics Working Group, which was very interested in the initiative – and they weren’t the only ones.

She said: “On a hedge-laying course recently I relayed to a farmer that Rainbow had launched a spiral recycling scheme and he was delighted. His relief was visible that finally one of the barriers to removal had been lifted. What to do with all the waste was no longer an issue.

“Now that the Rainbow scheme has been launched and has a web presence, we intend to write to all our past hedge planting grant recipients to encourage them to remove their spirals. We aim to offer them some kind of assistance, e.g. volunteer help, to clear the landscape of this waste and to recover valuable resources which can be made into something new.

"We are also working with landowners, e.g. Castle Howard, to trial alternatives to PVC spirals so that this problem is not perpetuated. We are going to need more volunteers to make our vision of ‘a landscape free from unnecessary, redundant and unsustainable plastic tree protection’ a reality. Recently Castle Howard staff ditched their day jobs for a few hours to ‘unwrap’ a hedge. It was a satisfying and cheery morning for everyone and led to a good amount of networking. We hope to do more of this sort of thing as it connects the people that live and work in the landscape to nature and environmental issues, quite literally, on the ground.

“If we can demonstrate how to make a difference to the amount of plastic in the Howardian Hills, then we hope other AONBs will follow suit. We are extremely proud that our enquiries sparked the creation of the first British PVC spiral guard collection and recycling scheme, and our thanks go to Castle Howard Estate and Rainbow Professional for collaborating with us.”