The results of Monty’s plastics pledge
With concerns growing over the amount of plastic polluting our natural world, Monty shares the results of his New Year pledge to reduce plastic use at Longmeadow
At the start of this year, I made a pledge to try to use as little plastic as I possibly could at Longmeadow. This was no small matter. Longmeadow, like every garden in the country, was awash with plastic. Not just plastic pots and seed trays − although there were thousands of those − but also plastic trugs, wheelbarrows, bags and labels. You name it, plastic, in some form, was playing a pivotal role in the garden. It is important to be clear as to why this might be a bad thing and why I wanted to cut back. Plastic in the oceans is reaching a crisis point. Great islands of the stuff are forming out at sea and there is scarcely a beach that is not awash with tidal plastic litter. Less visible, but just as serious, are the micro-plastics that are being consumed by fish. These are the tiny man-made particles used in things like toothpaste and cosmetics to help consistency and form, and which pass through the sewerage system and end out in the seas where they pass up the food chain until, irony of ironies, they get consumed by us again. Landf i l l is not much better. Vast quantities of land are filled with black plastic waste from gardens. This will not compost , although eventua l ly it biodegrades, albeit in something between 500 and 1,000 years. However, during that time much of it will filter into the aquifers and also work its way out to sea. This problem could be greatly alleviated if we could − and conscientiously did − recycle our garden plastics. But this is where there is the biggest hitch. Black plastic is difficult to recycle. But many plants demonstrably grow best in, you guessed it, black plastic. So, the industry sticks with black, we all buy our plants potted in black and then, because we cannot recycle them, throw them away. And so the plastic mountain builds.
Throughout this year I have tried various alternatives to plastic. This has involved pots made from wood chip or coir, soil blocks, loo rolls and egg boxes. Soil blocks are the best of the lot and they produce healthy plants, but involve quite a big initial outlay and a system that needs to be adapted for them. They are best for a block
about one inch cubed. Anything smaller is a fiddle and anything bigger dries out too much. Paper and wood chip pots were pretty useless as they disintegrated too fast, while slugs loved to eat them! Coir pots get too dry and it is hard to know if it is best to plant them pots and all, or to try and remove the rootball and in doing so potentially damage the tender feeding roots. Not satisfactory. Direct sowing and raising seedlings in a seed bed is a good idea but depends on having the right soil and weather conditions, whereas a container of any kind means you can work around the weather rather than be a slave to it. We have stopped using small plastic bags for things like compost or grit, wherever possible and, as well as making much of our own leaf mould and compost, we buy what we can’t make in bulk and reuse old bags. The major lesson I have learned from this year is that it is important to value what plastic you have as much as possible in order that it may be reused as much as possible. Wash it, store it carefully and treat it with respect. But the most important thing is to reconfigure our attitude towards plastic from a throwaway, disposable material to something that we wish to preserve and use for as long as possible. The real crime is single-use plastic in any form, in particular, single-use black plastic pots. Individually, the problem is modest. I have a lot of pots because we raise thousands of plants every year and buy hundreds more. But most gardeners only introduce a few pots into their gardens every year – perhaps a dozen or so, and rarely more than 20. However, the accumulated effect is colossal. UK gardeners buy half a billion plastic pots and trays every year, five hundred million separate plastic containers, a high proportion of which are thrown away every year after a single use and every single one is discarded sooner or later. And so the plastic mountain has become an Everest. Most plastic garden pots are made from around 80 per cent recycled material, taken from a variety of sources. They are therefore environmentally very efficient. It is what happens to them after we have used them that is the problem and that is down to their colour as much as anything else. Garden plants are mostly produced in black plastic
The major lesson I have learned is that it is important to value what plastic you have so that it may be reused
pots because it encourages excellent root growth. Roots are photosensitive so they try to grow away from a light source. In the soil this is easy, as the deeper the roots go underground the further they are from light. But in a container, the more they grow the closer they get to a light source via the walls of the plastic pot. Black plastic absorbs the light and blocks it more effectively than any other colour, so produces garden plants with the healthiest root system. Therefore, nurseries use it to produce the best plants possible and garden centres buy it so their plants are as alluring as possible, and gardeners buy it because − well, because they don’t really think about the pot at all. They just want a nice plant at a good price. It’s what happens next that’s the concern. Recycling is sorted using infrared light beams. These shine onto refuse that passes on a conveyor belt and identify material by light ref lection. Clear plastic shines the light back, which triggers a blast of air, which in turn blows the plastic into a separate bin for recycling. However, black plastic absorbs the light, so the air blast is not triggered and the pot ends up in the wrong bin. Hence, the difficulty recycling it. There are two possible solutions to this. The first is that we must all try to use as little plastic − of any kind − as we can. The most practical way of doing that is to look after and reuse your plastic containers as much as you possibly can. This cuts down the need to buy new plastic very effectively. The second solution is to find an alternative to black plastic. This is where the industry is focusing its efforts. A new taupe (that’s browny-grey to you and me) coloured pot is being trialled as a replacement for black, which does not contain the carbon pigment that infrared recycling machines fail to identify. The taupe pots will also have all their polypropylene derived from recycled material, and they can be recycled along with other plastics. So far, so good. But I have learned over the years that you can
A new taupe-coloured pot is being trialled as a replacement for black... which can be recycled
bully a horse to water but you cannot make it drink. It has to be thirsty. Which is to say, that for all the right-on environmental logic of using as little plastic as we can and for all the recycling that we do, if gardeners do not feel it produces as good plants, then they will not change. It has to be beneficial as well as right.
Black vs taupe trial
So, I have started a very unscientific, casual experiment at Longmeadow to see if plant roots grow as well in these new pots as they do in black plastic. I have planted Erodium, which has fibrous roots, teasel, which has a deep taproot, and Houttuynia, which has fleshy, underground stems (rhizomes) that bear roots, in both black and taupe pots using the same compost and left them to grow in the same place. I’m deliberately trialling this across a range of plants and, more importantly, root types so we can see whether some roots fare better than others. I will monitor their growth and make a call next year if the taupe works as well as the black. It will prove nothing other than being a rough first indication and I will, of course, share the progress both on these pages and via Gardeners’ World. I believe that real progress is being made. It is not too late for all of us to be part of transforming the way that we consume and recycle plastics. But it will take effort from everyone involved. The industry has to do all it can to provide an environmentally viable alternative, and growers and retailers have to support this by using them. Finally, we gardeners have to ask for containers that are not made from black plastic and, if necessary, be prepared to pay a little extra for that. But if we are not prepared to do this, then the environmental price that our children and grandchildren will pay is going to be truly catastrophic.
Monty’s plastic-free trial started in spring with making his own paper pots (right) then potting on seedlings into fibre containers
Clockwise from main pic: Monty trialled different ways to sow seeds, from fabric-wrapped coir Jiffy pellets, and biodegradeable fibre trays, to toilet rolls. Soil blocks proved effective in making sturdy seedlings, and are easily made with a specially designed hand tool
Clockwise from main pic: Plants grown in coir pots, such as this Fritillaria meleagris, are widely available. Recycled fibre pots gave a good start to dahlias. But if you have sturdy black plastic pots, Monty’s advice is don’t bin them – use them while they last.