Those black plastic pots are most likely the containers that comes to mind when talking nursery sales of potted plants. But today, the use of petroleum-based plastics can be both a social and an environmental faux pas. What’s a nursery grower to do?

Plastic waste is a serious problem worldwide, and recycling of plastics has not proven to be a solution. Overseas markets that accepted most of the agricultural plastics from the U.S. have stopped doing so.

The carbon footprint of plastic pot manufacturing depends upon what type of plastic is utilized to make the container. Polypropylene (hard, rigid plastic) requires more energy in its production than other types of petroleum-based products. Blow-molded containers are less rigid, have vertical ribs and are typically made from polyethylene, with a lesser carbon footprint (and are more readily acceptable in many recycling programs). There are pots available which are made from recycled plastic, reducing the amount of new petroleum-based plastic production.

Reduce, Reuse, Recycle

Ag waste recycling is possible for those black plastic pots. Customers may be inclined to recycle through their community’s programs, but some agricultural plastics are not readily accepted through many municipal programs. The type of plastic used is a concern, as is the black color of the pots, which cause difficulty throughout the recycling chain.

If your operation accepts pots returned by the customer, they’ll have to be washed, sorted and taken to the appropriate recycling facility or re-used. Offering customers an incentive to return pots, either with a discount for those who do or a fee that is refunded when pots are returned, may help increase the number of pots brought back after planting.

Reusing containers, rather than recycling, may be a more realistic option for many growers. It requires time, labor and resources to clean and properly disinfect pots to prevent contamination, and storage facilities to hold the containers until they are needed. It does, however, save on the cost of new containers each season.

Like recycling, reusing containers can be one way to demonstrate your environmental commitment and actively promoting either option can enhance customer buy-in and positive response.

USDA BioPreferred Certified

These products have been submitted to the USDA for inclusion in its BioPreferred Program, part of the Agriculture Improvement Act of 2018. The program’s purpose is to spur economic development, create new jobs and provide new markets for farm commodities. The increased development, purchase and use of bio-based products reduces our nation’s reliance on petroleum, increases the use of renewable ag resources and contributes to reducing adverse environmental and health impacts.

Nursery pots from several manufacturers are BioPreferred Program certified. Wood fiber pots, fiber pots coated with bioplastics and containers made from cow manure are all on the list. While many products are offered in small sizes for seed starting or plant starts, there are some products suitable to container growers offering mature-sized nursery products.

Considerations

Opting for environmentally friendly containers requires some consideration to the potential management changes which might need to be made to keep plants growing their best. University of Tennessee Extension has several “Beyond Plastic Pots” data sheets which list available container alternatives for nursery growers, and include information on container properties, longevity, suitability for automation and water needs.

Frequency and length of irrigation are factors to consider when moving from plastic containers to eco-friendly alternatives. The latter are often porous through the sidewalls, which is not the case in plastic containers, so water needs of the plant will be impacted.

Container strength and longevity, sizing which differs from standard, planted container weight and the containers’ ability to provide nutrients to the plant, or otherwise impact growth, are other factors to consider. Alternative containers absorb heat differently than black plastic too.

According to research, compostable containers are generally stronger than plantable containers, and can be stronger than some types of plastic containers. They also require less frequent irrigation, unlike fiber containers, which retain water when irrigated and dry more quickly.

Containers made from recycled plastics or bio-based plastics are known as known as R3 containers and can be recycled and reused. They function similar to petroleum-based plastic pots. An exception in this category is cloth pouches made from recycled plastics. These plastic cloth containers have the same water-retaining characteristics as compostable containers. They come in all sizes, including large sizes for mature trees. Root growth in these pouches will differ from that seen in rigid pots, potentially offering an advantage from root crowding and girdling.

Coir, straw, rice hull, bamboo and recycled paper are some of the media that are available to growers seeking environmentally friendly alternatives in nursery containers. While many pots are best suited to short-term use and planting or composting by the end consumer, others are able to accommodate perennial crops or can be reused in production.

The economics of switching to alternative containers will vary depending on your nursery’s production. Water use, purchase cost of containers, compatibility with automation and with your growing system (greenhouse, outdoors in containers, in-ground production) and impact on plant growth are considerations.

The range and availability of petroleum-based plastic containers should offer most growers the opportunity to try out an alternative that best meets your needs. Customers have shown willingness to pay a premium in many markets when purchasing eco-friendly options.