The 4 R’s of Sustainable Waste Management #4

As gardeners who support sustainable environmental practices, we affirm the 4 Rs of waste management: Reduce, Reuse, Recycle and Rot (i.e. compost). Last week’s article covered some of the challenges of basic recycling. This post will focus on recycling plastic garden pots and trays.

More than a decade ago, the Missouri Botanical Garden recycling program, estimated that about 350 million pounds of plastic is produced each year for the horticultural industry alone. Then and now, this “green” industry is not so green.  Although plastic gardening containers can be used again, the sorting, cleaning, and disease control required for reusing these materials can be problematic. If they are simply tossed into landfills, they will take up space and not decompose for decades. Recycling is a critically important option.

Plastics recycling has an interesting history, beginning in the 1970’s with the first recycling plant.  Curbside pickup of plastics began in major cities in the 1980’s, with increasing focus on plastic sorting technology and codes for different types of plastic. Today, nearly all Americans are able to participate in a plastics recycling program.

The universal recycling symbol—the familiar three folded arrows with the head of one arrow pointing to the tail of the next—was developed in a contest linked to the first Earth Day in 1970. The triangular symbol used to identify different types of plastics dates from 1988. The numerical ID code does not mean the container is made from recyclable plastic, nor does it mean the plastic is recyclable. Rather, it indicates the type of plastic resin used to make the product. Recyclers sort plastic containers by code to keep different resin types separate, which in turn helps to achieve the end-use product with the highest value.

See the full breakdown of each kind of plastic along with its associated code here. For a quick tutorial, check out this two-minute YouTube video.

There are three types of plastic commonly used for horticultural products:

  • High density polyethylene (HDPE) #2,
  • Polypropylene (PP) #5, and
  • Polystyrene #6, a lightweight plastic that is difficult to mark with a recycle indicator. It is most commonly used for trays and seedling cell

When recycled, plastic pots are ground into chips and melted. They must be sorted because different types of plastic melt at different temperatures and some do not melt at all. Furthermore, the pots must be clean (no soil residue) and free of any metal rings, clips, or hangers.

There’s no denying that horticultural recycling can be a tedious and complicated process, and many garden centers and growers just find it too much trouble. Identification codes on pots are small and hard to see, some pots are made of composites that cannot be recycled, and recycling centers may not accept all plastic resin types. For example, the local Rivanna Authorities accept only #1 and #2 plastics, in addition to some plastic films and bags. Nevertheless, recycling is worth the effort when considering the amount of plastic we continually add to the environment. Some garden retailers are doing their part to make the process easier.

For example, Lowe’s home stores, including the Charlottesville and Waynesboro stores, provide a cart at their garden centers where any plastic plant trays and pots can be deposited, even if the plants were purchased elsewhere. Lowe’s vendor Metrolina Greenhouses transports the containers to North Carolina, where they are sorted, sterilized, and reintroduced to the production cycle. Material not deemed reusable is crushed, banded, and sent for recycling.  According to Chris Cassell, director of corporate sustainability for Lowe’s, the company captured more than 9 million pounds of plastic for reuse in 2018.

Home Depot also has a plastic pots recycling program, which started in 2009. Customers can bring their empty pots to any store nationwide. Home Depot partners with East Jordan Plastics Inc., which turns the containers into new pots, trays, and hanging baskets. Every year they recycle more than 15 million pounds of used material. NOTE: The Home Depot in Waynesboro is currently not accepting pots due to COVID-19 concerns.

By recycling plastic pots and trays, households and growers can prevent tons of waste from ending up in landfills. Be careful not to “contaminate the batch.” Remember to remove all loose soil from plastic containers, ideally with a quick spray of water, and take off all paper labels and metal wire or clips.

Also remember that recycling is the R of last resort in sustainable waste management. As consumers, we need to think about ways to reduce the use of plastic pots. For instance, we can buy plants in eco-friendly, compostable pots or purchase bare-root options when possible. And we should always reuse whenever possible.

We all know the world has a big problem with plastics pollution, and it is easy to become discouraged. But we might be on the brink of exciting times when it comes to developing sustainable plastic. Take a look at this article and this YouTube video to learn more about the power of microbes and methane!

As gardeners, we care about our landscapes and the earth that sustains us. Recycling plastic pots is just one way to be a conscientious gardener. Check back for next week’s post on food waste and composting. And a reminder: it’s not too late to join the international Plastic Free July Challenge.