Reducing Plastic Waste in the Garden

Blog by Franki Appleton

The Wheel Project Manager

As gardeners, we love nature, wildlife, and all things natural and decomposing. And yet, so much of our hobby involves plastic! In this blog we investigate which horticultural plastics can be reused, which can be recycled, and offer some ideas for plastic-free garden swaps.  

Horticultural plastics are everywhere. Plant pots, seed trays, plant labels and markers, bags from peat-free compost and other growing media, horticultural fleece, weed membrane fabric, even some gardening twine are all made from plastics. Plastics are very durable, waterproof, easy to clean, and have been cheap to manufacture, making them very useful in the world of gardening. The fact that plastics cannot decompose is also its downfall, when older plastic starts to disintegrate to smaller pieces littering our gardens, contaminating our soil and waterways, and harming wildlife. But there are some circular economy practices and swaps to limit the new plastics we bring into our gardens. Here are some options to reuse, recycle, and refuse horticultural plastics.     

Reusing and Sharing Existing Plastics

While lots of plastic items can be reused in the garden, those of us who have been gardening for many years often end up with more than we need, with mountains of plastic plant pots and plant markers cluttering up our sheds.

One option for sharing your plant pots with other gardeners in need of different plant pot sizes, or with people new to gardening, is to use our new Plastic Plant Pot Library built by volunteers at Mitcham Community Orchard and Gardens. You can drop off your plant pots to an empty shelf on the library, or pick up new-to-you pots any time the orchard is open. See our events pages for the orchard open days.

You can also pass on any surplus reusable plastic garden items to others for free using online communities such as Facebook Marketplace, Freecycle or your local neighbourhood WhatsApp group. 

Which gardening plastics can be recycled?

When a plastic plant pot or seed tray starts to crack and break, most of us will have a strong desire to dispose of them sustainably. Sadly, not all of these garden plastic items can be recycled in curbside collections, and some of them cannot be easily recycled at all. 

Did you know that black plastics are particularly difficult to recycle? This is because recycling sorting machines cannot read the black colouring and will not identify the item correctly. That means that black plastics cannot be recycled in your curbside collection. Many plastic plant pot manufacturers are phasing out black plant pots in favour of grey to fix this issue. 

Recycling symbol 1 (PET), recycling symbol 2 (HDPE), and recycling symbol 5 (PP) are more easily recycled and are collected at curbside in Merton. If your plant pot does not have any of these symbols etched on, then sadly they cannot be recycled at curbside. 

It’s also important to watch out for plastic-style items that are labelled as compostable. These plastics cannot be recycled as they are made from a different substance as plastic. What’s even more frustrating is that they are often not home-compostable, but can only be composted in industrial composting machines.   

But as more and more people and businesses learn about the power of waste reduction and the circular economy, schemes are being put in place to give people more recycling options for hard-to-recycle plastics. In 2024 B&Q launched their plastic plant pot recycling scheme, installing plant pot recycling stations at some of their stores for people to drop off unwanted plastic plant pots. These plant pots are then recycled and used to create brand new pots.

Some garden centres also offer this plastic plant pot collection, as well as collections for empty compost bags.    

Plastic-free gardening swaps

For those gardeners wanting to stop using new plastics where possible, there are garden-friendly alternatives.

Plastic plant labels - Switch to bamboo, or wood, which can be composted when they are old and tired. If you are ever given wooden takeaway cutlery, these make excellent markers and can be written on with a marker pen.

Plastic twine - Jute twine is made from natural fibres which will break down over time. This is preferential as plastic twines which last longer can end up digging into the bark of trees, causing injury to the branches. 

Plastic seed trays - Seedlings can be started in egg boxes, or for plants that don’t like their roots to be disturbed try using toilet roll tubes. You can even make your own seedling pots using newspaper. If you’re a dab hand at woodworking, why not make a shallow wooden seed tray you can reuse for many sewing seasons.

New plants arriving in a plastic pot - Opt for buying bare-root perennial plants, or grow your own seeds from cuttings and divisions. If your neighbour or friend has a plant you like that can root from cuttings or where the roots are clump forming and can be divided, ask them if you could take a little to start your own!

Weed membrane fabric / landscape fabric - Avoiding the use of landscape fabric will avoid plastics and also benefit the health of your soil. Soil needs air circulation, and you will often find that soil under weed suppressing fabric is dry and compacted, with less ability to soak away surface water. A plastic-free alternative is to opt for the “Back to Eden" method of laying plain cardboard or newspaper layers followed by a thick layer of woodchip mulch. This will not stop weeds entirely, but will make those that do pop up very easy to pull out.    

Horticultural fleece - This is used to insulate plants that aren’t fond of our cold winters. Other options to ditch the fleece include using natural hessian fabric, newspaper, and straw. 

If you want to join our community of sustainable gardeners and orchardists, join us at one of our growing sessions at Mitcham Community Orchard and Gardens or our other community growing spaces in Merton.