Plastic substitutes

If not plastic, then…. what?

So far I’ve been concentrating on what to do with the plastic you’ve already got.

But once you’ve taken the pledge not to buy any new plastic for your garden (and done your best to fend off the plastic that keeps trying to get back in) you still need pots, and seed trays, and hanging basket liners. So if not plastic, then what?

Smaller pots – anything up to about 7cm – are easy. You can make them yourself: save your loo rolls, make newspaper pots, or use a soil blocker. Small plastic pots and module trays were the first things I got rid of in my garden: I no longer use them as I find the alternatives so much better. I’ll be detailing how I did it soon on this very blog.

Larger pots, though, are tricky. You can’t make them yourself: so you have to buy them in. And most of the pots you’ll see offered for sale at sizes 10cm and above are plastic.

That’s not to say there’s no alternative to plastic pots: actually, there are loads, they’re just quite difficult to find. The stranglehold plastic has over the horticultural industry is loosening off, just a teeny bit, and most garden centres now sell at least some biodegradable pots. But if you look into it more closely, the choice is actually quite bewildering. I have found just under a dozen different biodegradable materials currently used as a replacement for plastic in gardening products. Here’s the list:

  • coir (coconut fibre)
  • miscanthus
  • spruce wood
  • bamboo
  • rice husks
  • straw
  • cow manure
  • starch
  • cellulose
  • cardboard
  • terracotta clay

Some of these sound like they might be the same thing, but nonetheless – it’s quite an impressively varied choice.

Why we are still using so much plastic when there are so many other types of pot out there I’m not entirely sure. Part habit, I’m sure; but also because biodegradable pots are definitely more expensive. This is mainly because most biodegradable pots, ahem, biodegrade; so they don’t last very long and need replacing each year as they are planted along with the plant. That’s not the case with all of them, though: clay pots are the obvious example of a long-lasting biodegradable pot, and there are others which claim a life of at least 3-5 years.

The clincher for me, though, and one that justifies the extra expense is that quite a few biodegradable pots are an improvement on plastic. When plant roots can breathe (as they cannot in plastic), when they can grow through a material rather than being forced to circle round and round (pot-bound plants are a thing of the past when you grow in many biodegradable pots), and most importantly of all when container and plant can go into the ground together with no need for root disturbance – that means a happier plant that’s more vigorous, healthier and quicker to establish in the garden. I can bear witness to this myself: my results, especially at the beginning of the year when I’m sowing, pricking out and transplanting hundreds of plants, have noticeably improved since I stopped using plastic.

Not all these advantages apply to rigid biodegradables like clay or bamboo, but you still keep some. I find when growing in clay pots that the plants seem to appreciate the increased exchange of air and moisture through the sides of the pots, and though they dry out more quickly they also wet more thoroughly than plants in plastic pots, as the clay absorbs the water as well as the compost. That means you don’t get that effect of water running down the sides between rootball and pot before draining out the bottom and leaving the roots as bone dry as if you hadn’t watered at all.

The more I grow in biodegradable containers the more I like it. But having tried a few different types in a rather haphazard way over the last few years, I’m also aware that they are not all alike. There’s a big difference between growing in a floppy coir pot and a rigid terracotta pot; and there are other considerations too. Rice hulls have a very different environmental footprint to cow manure, for example.

So I am going to be spending the next few weeks collecting together information about as many of the biodegradable alternatives out there as possible. I’m also going to get my hands on a few samples of the pots in question and put them through their paces. The result, I hope, will be the most comprehensive analysis yet of exactly what it’s like to grow your plants in non-plastic materials; which are the best, which don’t perform so well and which you should be using in your garden.

Plastic-free gardening

Making a start

There you are, faced with the mother of all plastic mountains just inside your garden gate. You have gardened with plastic so long you have no idea how to live without it.

Yet you’ve watched the albatrosses choking and the poisoned whale calves on Blue Planet II; you know plastic is cluttering our seas and turning our beaches into rubbish tips. Besides, it’s kind of ugly. So you want to wean yourself off the stuff and find some prettier, more planet-friendly way to be.

But where on earth to start?

1: Stop buying new plastic

Take a pledge, like I did at the start of 2017, never to buy new plastic for the garden where there is an alternative.

2: Use up all the plastic you’ve already got

You’ll notice I’m not saying “stop using plastic”. Just stop using new plastic. Reusing the plastic you already have until it gives up from sheer exhaustion means you are maximising the amount of time it stays out of the wider environment. I have plastic pots in my garden which I brought with me when I moved to Somerset over 7 years ago and they’re still going strong (if slightly battered, these days).

3: Recycle your spent plastic… and don’t replace it with new

When plastic items (inevitably) crack or degrade to the point where you can’t use them any more they should go for recycling and be replaced with an alternative that is not plastic based if possible, or with recycled plastic where necessary.

4: Find non-plastic alternatives

This is not as easy as it sounds. There are alternatives: lots of them, from biodegradable plastic to bamboo, wood, clay, glass, metal… Not all are equally desirable from an environmental point of view, and some perform better in the garden (often better than plastic) while others perform worse. Mostly, I’ve not been looking for improvements: just non-plastic equivalents. I’ll be weighing them up one by one on this very blog.

5: If there’s no non-plastic alternative, find a getaround

There are some gardening tools and equipment for which I haven’t – yet – found an alternative that isn’t made from virgin plastic. On the list: Compost bags, fruit netting, insect-proof mesh, bubble wrap greenhouse insulation, build-a-balls and other support connectors. For at least some of these, you can get around the issue by simply finding a way of gardening that doesn’t use that product. I’ve stopped using bubblewrap insulation, for example, simply by not heating my greenhouse any more.

6: In extremis, use recycled plastic

I have much to say about recycled plastic, of which more later. It is not the panacea it is sometimes made out to be, and I would argue it is the bottom-most rung on the ladder to plastic-free nirvana, the absolute minimum you can do to reduce the amount of new plastic in your garden. But at least it’s something, and better than buying in new plastic all the time.

7: And watch out for uninvited plastic

By this I mean all the plastic which arrives in the garden by accident, as it were, without you inviting it in. Every time I do a planting job for a client I am lumbered with sometimes hundreds of 2 and 3 litre pots: new plastic I haven’t directly “bought” but which nonetheless are now adding to my garden’s plastic footprint. I will never use these pots: there are simply too many of them. It makes them effectively single use plastics – a real waste of the resources required to produce them.

And every time I mail order in plants, tools or just about anything for the garden they will be wrapped in single-use plastic film. I even ended up with a pack of biodegradable coir pots once which arrived beautifully shrink-wrapped in plastic, rather cancelling out the reason I’d bought them in the first place.

Plug plants are particularly bad, held in big PET2 rigid blister packs which cannot be recycled kerbside or even at my local tip (there will be more about the thorny issue of recycling garden plastic shortly, too).

So to tackle this tide of uninvited plastic, the only place to go is the supplier. I am actively seeking out wholesale nurseries who use only recycled pots (or better – but vanishingly rare – no pots at all). Garden centres are another behemoth to tackle: I have never even heard of one with a no-plastic or even recycled-plastic policy. If you know better, do tell!

And I will be finding mail order suppliers who use corn starch and cardboard for packing or who use plastic alternatives where necessary. This is quite likely to be difficult, if not impossible in todays world; so if you know of any specialist plant nurseries or mail order companies with a no-plastic mail order policy, please let me know in the comments below…