Earthworms’ Castings: Why We Can’t Recycle Garden Pots

By Jean Ponzi

Very sorry to have to report that our regional Plastic Pot Recycling remains suspended.

Fellow gardeners, I know you are sustainability minded — and practical. I hope this summary of issues and some options will be useful, even while we cannot recycle our pots. 

Wasn’t Plastic Pot Recycling “suspended” in spring 2020? Why is it still not happening? 

The collection program did not re-start as usual last spring. One factor at that time, as our society was going into the COVID-safety shutdown, was concern about coronavirus transmission on plastic surfaces. We now know this is not a pandemic control focus.

The other big issue from last year persists. Markets for recycled plastic are extremely depressed, globally. If there are no markets wanting to buy and use a recycled material, collection systems become unsustainable. The whole cycle has to be working for recycling collection to function.

We can recycle plastic food and beverage containers, so why not pots? 

This is a really good question, with three main answers:

The mix of plastic resins used to make garden plastic pots, trays, flats and cell-packs includes some of the lowest-value types of plastic. These resins are cheap to mold into containers durable enough to support commercial movement of plants, but not suitable to re-manufacture into a next generation of useful items. 

Most garden plastic containers are black. The Material Recovery Facilities that sort and process the items accepted in our home recycling systems use sophisticated optical scanning equipment to efficiently sort the huge volumes of mixed plastic items we send to them from our single-stream bins. Optical scan beams can’t “see” through black plastic, so this equipment can’t sort garden plastic items in the same way it sorts bottles, jugs and the other household plastic items we recycle at home.

Dirt remains in most garden pots even when we dump them out. Our recycling industry service providers ask us to put stuff into our bins that is “empty, rinsed and dry.” Soil residues will contaminate this material stream, endangering the recycling systems we rely on every day. 

My local garden center still has a pot recycling trailer. Why is it there if we can’t bring in pots?

The network of garden center partners has been one of the strongest contributors to this very specialized local recycling program. How great that we could bring back pots to be recycled on a trip to get more plants! Convenient for us and good business for these locally owned, trusted expert advisors on our planting choices! Most of these valued partners have been willing and able to keep a trailer on-site. Please don’t bring them pots while the program is suspended!

Is Missouri Botanical Garden still accepting pots? 

No, the Garden is not. In 2017, the Garden turned over operation of the Plastic Pot Recycling program it started to an established local recycling company that has special expertise with plastics. This move made sense for many reasons, transferring equipment and systems to a business Garden sustainability leaders vetted as the best possible local operator of this kind of special-waste program. 

Downturns in the global recycling system, especially over the past couple of years, would have had the same – if not a much worse – effect on the program if the Garden was still running it.

The Garden did continue to promote the program, and will promote it again, if and when it can resume. Most importantly, the staff of the Garden’s EarthWays Center, including myself, has continued to research and track these issues. The more we understand, the better we can contribute to sustainable solutions as opportunities arise, around our community and beyond.

What about alternatives to plastic pots? 

This seems like a logical question, but it runs up against a tough situation. Plastic has become a reliable low-cost way to get live plants from growers to gardeners in top condition, through intensive handling and shipping systems. We need to think about the total costs of using a material that’s so “cheap” to make and use that its worth in recycling has dropped to a negative value. This is a key consideration for dealing with plastic pollution overall.

There are alternative efforts are in the works, for example:

The Sustainability Committee of Association of Professional Landscape Designers (APLD) reached out to us at the Garden in 2018, having learned about the recycling program we developed. 

APLD’s green leaders want to understand these issues and tackle options to reduce plastic waste, from the strength of their work across the horticultural industry. Read the white paper APLD produced to learn more about the issues surrounding garden plastic waste. 

APLDs Healthy Pots  Healthy Planet initiative is mobilizing their national network of professional members to address garden plastic waste issues. Linked from this APLD webpage watch an interview with Marie Chieppo, author of the pots issues report. 

Plant production systems that don’t rely on plastic pots are working, though still on a limited scale. 

One of our region’s largest growers and plant wholesalers, Jost Greenhouses, has been using the Ellepot equipment and materials system, developed in Denmark, for several years. The Ellepot system produces plants in compostable wraps and reusable trays. Jost’s landscaping company customers experience a 30-40% efficiency in labor costs as they install these “potless” plants. 

On Missouri Botanical Garden’s Horticulture team, Greenhouse Manager Derek Lyle continually works to cut plastic pot waste. Evaluating the kinds of pots needed led to streamlining the variety of pots used, which also facilitates re-use of pots in Garden growing programs. These shifts have cut supply costs, especially as the cost of plastic products has increased. 

Local garden centers are trying alternatives. Ask your favorite locally-owned garden center about these options – especially as you select native plants to grow biodiversity in your yard! 

While I can’t recycle them, what can I do with my pots?

If you have the space and inclination, hang onto them. Our regional Pot Recycling program is suspended at this point, not ended. If and when the recycling market situation improves and Pot Recycling can restart, The Healthy Planet and the Garden will get the word out.

If you can’t or don’t want to hang onto pots as you’re planting this spring, please DISPOSE OF ALL GARDEN PLASTIC IN LANDFILL TRASH. Never put garden plastic items into your household single-stream recycling system. Thank you!

Can I donate my empty pots to a community garden group?

Maybe, if you have a relationship with the group, and you know they can use your pots. Check with gardening groups you follow on social media or use an app like Nextdoor. Remember there are a LOT of empty plastic pots and other containers generated during every growing season. 

Pots come in all shapes and sizes, making them almost impossible to efficiently stack and store. If you explore this option, be sure that feeling good about passing along your pots will truly benefit whoever agrees to take them. Do keep some pots on hand for plants you plan to divide and share! 

What else can I do?

Educate yourself about plastic production and waste issues. View Story of Plastic, a documentary directed and produced by Deia Schlosburg, an alumna of Washington University.

Be gentle with yourself as you deal with plastic issues. Yes,, this is hard news to read. Our region has had a Plastic Pot Recycling option since 1995. Although the program persisted and evolved here, the fact that it has never been replicated elsewhere in the U.S. underscores the issues associated with this special waste stream, and with plastic waste overall. Consumer choices matter, but they are only one element in a complex set of issues.

If you have additional questions or would like to discuss these issues, please reach out to the Garden’s Green Resources Info Service by email at greenresources@mobot.org or by phone at 314-577-0246.

Enjoy your garden and let Nature’s wisdom refresh and sustain you!