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Is it curtains for plastic flower pots- especially black ones? 

  • Contacting us online

Elaine Watson 

For gardeners who care for the environment, surely it is time never to buy plastic plant pots or seed trays again? Why do we as some of the most caring, creative and ‘green’ people - yes, gardeners - use black plastic plant pots? Because we can’t help it! Because we don’t even notice them and see beyond the pots to the gorgeous plants. Because we think there is no alternative on offer. Flower pots become a problem really easily because displays of flowers and plants are so seductive and impulse-buying happens in a flash before the conscious brain intervenes. How do we learn to curb the impulse-buying which later results in the misery of realising our sin and much soul searching in shame? 

Up until the mid-20th century, gardeners would shop at small local nurseries, which would sell plants in a sack or as a bare root. Because of this, sales were generally limited to the early spring or the autumn. I remember cruising around the countryside outside London in the early 60s and my mother insisting that we stop whenever she saw a handwritten ‘nursery’ sign by the roadside. We would look at someone’s garden plot and select plants which would then be dug up and wrapped in damp newspaper. Sometimes we children in the back of the car could hardly breathe as we embraced these damp bundles of precious plants. As the number of people with garden space began to rise, alongside the post-war housing boom of the 1950s and 60s, the sale of plants in pots began to take off. People started to grow ornamental plants rather than essential vegetables in their gardens. Gardening became a hobby.  At first nurseries would sell plants in jam jars and makeshift containers. And then came the explosion and the modern garden centre was born, and it could tap into the new plastics industry which made life so much easier. (Apparently in 2017, families spent £6bn on garden products: £1 in every £100 of household spending. One in every 62 jobs is reliant on garden centres. The horticulture industry is, at £24bn, bigger than aerospace! ) 

(From research by the HTA- see website details below.) 

Plastic plant pots have revolutionised the horticultural industry as they are light to transport, easy to clean, and of consistent size. Dark plastic pots maintain the root systems of plants in good condition, and keep the plants hydrated. Quite apart from so many of us buying plants in plastic pots and trying to reuse and recycle them, the possibly surprising cry from the Somerset Waste Partnership which operates the local recycling plants is ‘PLEASE do NOT recycle flower pots’!  ‘Please reuse and re purpose if possible’. But of course, plastic pots eventually do fall apart and then they are useless and are sent to recycling by the conscientious amongst us. This is when they go into landfill and persist for decades. What we probably don’t think about is that most flower pots put out as ‘rubbish’ are currently nearly all made of black plastic which can’t be recycled and also are probably not washed. Unwashed flower pots mess up the machinery as you can imagine- the grinding surfaces get damaged by soil and stones left in the pots. Plastics are sorted by light beams and black plastic is not recognised as anything and by-passes the sorting process, so black pots end up in landfill and are not recycled. Surely most gardeners would be horrified to know that? Conscientious manufacturers are devising different colours- taupe being a current alternative- but even these are very energy-greedy for recycling.  When China woke up and refused to take plastic for recycling from the UK, the recycling industry was put into a frenzy, but ‘luckily’ for us Turkey and Indonesia stepped up and so these are the destinations for our discards. But at what cost to the natural environment in these beautiful countries? We need to eliminate ALL plastics from the horticultural industry. 

 What are plastic flower pots made of?  

Plant pots are usually made from High-Density Polyethylene (HDPE) or Polypropylene (PP) and are harder to recycle than the Polyethylene Terephthalate (PET) from which plastic drinks bottles are made. (I think you need a PhD in polymer science to know how to distinguish one type of plastic from another!) 

 The types of plastic in common use are:  

  1. Polyethylene Terephthalate (PETE, PET) 

  1. High-Density Polyethylene (HDPE) 

  1. Polyvinyl Chloride (PVC – U) 

  1. Low-Density Polyethylene (LDPE) 

  1. Polypropylene (PP) 

  1. Polystyrene or Styrofoam (PS) 

So what’s the problem with black plastic? 

The black plastic pot cannot be recycled through kerbside collections, due to the inability of PIR sensors (passive infrared sensors) at recycling facilities to recognise any plastic which contains a carbon-black pigment. Black pots can’t be sorted. But actually all polypropylene (PP) is recyclable- including black plastic.  However, the market value of dark PP is so low that recyclers prefer not to deal in it. As it can’t be sorted automatically, it has to be collected in bulk from collection points. In addition, dark colour PP can only be turned into more of the same thing, rather than a range of colours. Basically, the lighter the PP colour the easier it is to recycle. Hence the taupe flower pot was devised as an interim solution for recycling flower pots. 

Interim solution-the birth of the taupe pot 

What is ‘The Taupe Pot’?  

The taupe pot is a light-coloured polypropylene pot which can be produced by any plastic plant pot manufacturer with the capability to fulfil the required specification. The pot is 100% recyclable and made from as high a percentage of recycled polypropylene (PP) as possible, frequently from a UK source, with little or no virgin material. The pot is designed to be kerbside recyclable where possible and to replace the traditional black plastic plant pot currently favoured as an industry standard by ornamental plant producers.  

Who Decided on Taupe?  

The taupe pot was selected at a Nursery Working Group meeting, which is a grower-led group. The Horticultural Traders Association (HTA), which is the trade association for the UK garden industry and has an excellent website, facilitates the group but does not guide the policy that is decided. The idea is that any plant producer can ask their chosen pot manufacturer to supply them with a taupe pot, as a replacement for black, as long as it fits the specification. The colour was selected as the most appropriate to replace black. Therefore, no single manufacturer or grower has any exclusive right over the taupe pot, it is an industry-led solution to an issue facing horticulture. The taupe pot represents the best option for recycling at this moment in time. The ultimate aim for resource management would be to create a circular economy for recycled/recycling plastic within the horticulture industry, which is sourced in the UK, recycled in the UK, re-manufactured in the UK and sold in the UK. The taupe pot is a start to this, and the industry, facilitated and assisted by the HTA, hopes to build on it in the future. This could be a good starting point for us as plastic-free ambassadors to encourage local garden centres to sign up to this initiative. 

Is it more expensive?  

Generally, the taupe pot (and any ‘accredited’ non-carbon black pigment pot) is around 25%-30% more expensive to buy. However, this translates into an average of about 1.5%-2% more on the end user price for each plant. The expense relates to the raw material cost of UK-sourced recycled PP, not the cost of making. Most buying public would probably not even notice this cost increase, and it has been shown that more are likely to accept it without question. It is also worth noting that the more material goes into the UK waste stream, the more will be available for manufacturers and the cheaper it is expected to be. An ‘accredited’ pot means it has been tested by RECOUP as being able to go through a recycling facility’s PIR sensors. 

Some garden centres are taking part in a collection scheme run by Ecogen to take in used plant pots (whether black or not), pallet them up and send them off to the appropriate waste recycler. Information can be found on the HTA website. 

Otter Garden Centre at Norton Fitzwarren, Taunton (01823 323777) is working on a recycling scheme.  

So what are the sustainable alternatives that we could use?  

Surely it is actually much better to go sustainable, to buy or make (peat-free, obviously) compostable pots and seed trays? In so doing we are cutting waste, reducing plastic waste and of course saving money. The alternatives come in all shapes, size and materials, from coir and cardboard, straw and newspaper, to toilet rolls, cow pats, rice hulls, egg shells, fruit rinds and more.  

COIR POTS and other sustainable pots.  

The Hairy Pot Plant Company based at Kirton Farm Nurseries Ltd in Winchester, Hampshire, grows herbs and cottage garden plants in 'hairy' coir pots. The pots are planted straight into the ground so there is nothing to throw away. They are passionate about conserving the environment and working and living in a more sustainable way. The company experimented with pots made from rice husks, pressed peat, pressed cardboard, Miscanthus and coir fibre before choosing the coir fibre pots. These are made in Sri Lanka using waste husks from coconut farms. Each pot is handmade and dipped in organic latex, from local rubber farms, to keep the fibres together. The pot manufacture creates local employment. But, the pots still have to be transported hundreds of miles for use in the UK. We need to look at local materials such as Miscanthus which could be useful as an equivalent to coir in the UK. Of course we have the very exciting Biohm project on our doorstep in west Somerset, (Watchet Biomill) which is currently manufacturing insulation materials out of waste products being digested by fungal mycelium, but whose long-term aspiration is to find a means of digesting plastics into their natural components. The mycelium product is water-proof and biodegradable so could also be a useful extension of their project for the horticulture industry!  

The HTA has an excellent website and much of the above information can be found there: https://hta.org.uk/news-current-issues/sustainability-roadmap/recycling/plastic-pot-initiative.html