Have you ever wondered what happens to all those plastic pots once we’re done with them? I was under the false impression that most were recycled. As it turns out, a large percentage of them join other single-use plastics in landfills. That’s according to Jean Ponzi, Green Resources Manager in the sustainability division of the Missouri Botanical Garden.
Years ago, Ponzi asked herself the very same question. What followed was the launch of the largest plastic pot recycling program of its kind. Since 1998, the Missouri Botanical Garden’s Plastic Pot Recycling Program (MOBOT) has prevented over 300 tons of plastic from reaching area landfills.
Unfortunately, it’s only made a small dent in the problem.
PLASTIC WASTE IS PROJECTED TO DOUBLE
According to the EPA, in 2017, the U.S. produced 35.4 million tons of plastic. Of that, about 26.8 million tons, or 76 percent, went to landfills. This mean that, of all the plastic produced, only 8.5 percent was recycled.
Until recently, China bought most of our plastic waste and recycled it into new products. But in 2017, the country went from purchasing 60 percent of our plastic to 10 percent, drastically increasing the amount sent to our U.S. dumping grounds. This amount is now expected to double over the next two decades.
THE SCIENCE BEHIND PLASTIC POTS
There’s no doubt that the black plastic pot changed the horticultural industry. It’s easy to transport, lightweight and flexible. Plastic, in fact, was a game-changer for a wide range of household products. Containers are today one of the major products the plastic industry produces.
Yet with all the convenience plastic containers represent, there is currently no national infrastructure for processing our plastic waste. And when it comes to black plastic pots, there’s an added dimension. Since they’re dyed with carbon inks that can’t easily be broken down, black plastic pots are non-recyclable. That makes them a single-use plastic, which takes around 450 years to decompose.
Enter Marie Chieppo, Principal at EcoPlants Plans, and participant in the MOBOT program. She decided to dig deeper into what goes into recycling plastic pots and why the process is so problematic. What she discovered is an eye-opener for us gardeners.
HOW TO KEEP PLASTIC POTS OUT OF LANDFILLS
According to Chieppo, where it comes to recycling, all plastic pots pose a problem. Since they are derived from fossil fuel hydrocarbons, they are non-biodegradable. Further, in order to be able to be recycled, they must be:
DECONTAMINATED – that means all soil and debris must be removed from the container. Anything that stays in the pot wreaks havoc on recycling facilities by dulling the knives of the grinding machinery.
SEPARATED BY COLOR AND DENSITY – each of which can have an effect on how a pot can be recycled.
STACKED – this can be a nightmare because they’re all configured differently. Plus they take up a lot of room in the recycling bin.
ABLE TO BE RECYCLED – some can be reused, but most cannot (as in the case of black plastic pots), says Chieppo. For example, you can’t mix polymer types. That’s because there are three primary resins used in the manufacture of horticultural pots. And each is processed differently.
The net result is that recycling plastic pots is a very expense and labor-intensive process.
‘The sad truth is that 95-98 percent of plastic horticultural pots end up in the landfill,’ says Chieppo.
WHAT GARDENERS CAN DO TO HELP
So what can gardeners do to mitigate the problem? Until a better plastic is developed, we can try our best to recycle. To do so, we need to educate ourselves first as to the process. For instance, we must never mix horticultural products with other plastics.
Instead, we must first wash and disinfect our used plastic pots to kill any plant pathogens. Then we can put green, blue or red plastic pots out for recycling. But black plastic pots and trays must be thrown in the trash.
ALTERNATIVES TO PLASTIC POTS
Can anyone unseat plastic? Several manufacturers are trying. Some are now producing new pots out of ‘Bioplastics’ (a hybrid starches combined with petroleum). Other companies are manufacturing compostable pots, plantable pots and pots made from cow manure among other things. All of these alternatives can produce and grow plants as well as plastic ones.
Plantable pots are an option growing in popularity
But before we can begin making a dent in our plastics waste problem, companies will need to mass produce them. This process has yet to be developed. For now, the best way forward is to educate ourselves as to viable alternatives to plastic pots and to recycle the ones we do use appropriately.
‘It’s not an Either/Or’, says Chieppo.
To see photos of my garden designs, including plant lists, check out my Instagram at carole.herebydesign. I post seasonally from spring through fall.