The Real Green Industry: Plastic alternatives

Traditional plastic nursery containers are a vital part of production. They’re lightweight, they work with automation and growers are comfortable with them. Alternatives to plastic pots are not new. Some growers have been using them successfully for years. But with sustainability on everyone’s lips, retailers and consumers are asking about containers that won’t sit idle in the landfill.

We’ve outlined a smattering of the alternative products.

Spruce up production

Fertilpot from Fertil USA is made of spruce fibers and doesn’t contain glue or binders. The wall of the pot is porous, so drain holes are not necessary.

“This allows the root structure to develop in its natural shape,” said William Evans, sales manager of Fertil USA. “Fertilpots are a container that will not ‘containerize’ a root structure.”

Airflow on the outside of a Fertilpot promotes root pruning, which encourages a more fibrous, branched root structure.

The biodegradable pot can be planted directly into another pot for shifting up or directly into the landscape. When shifting up, the top of the Fertilpot should be buried slightly below soil grade to prevent any wicking effect. For plants in which the crown has to be level with the soil (and in that case only), the top edge of the pot can be easily removed by hand. Compress the soil around the Fertilpot to limit drying out, then water thoroughly. Make sure the pot does not dry out during the first few days until the roots have started to extend beyond the pot.

Carlton Plants in Dayton, Ore., started using Fertilpots about two years ago. The nursery uses them primarily for hydrangeas, lilacs and shrub seedlings and rooted cuttings.

“The roots penetrate the Fertilpots really easily,” said Mike Anderson, Carlton’s propagation manager. “The pots ease the transition of going into field production.”

Transplant survival rates also increased with the Fertilpot, he said.

It also reduced handling of the plants because there’s no plastic pot to throw out before transplanting

Carlton Plants also uses Jiffy peat pots. Jiffy pots are made of sphagnum peat, wood fiber and lime to adjust the pH.

Fashionable and practical

Sweetwater Nursery in Sebastopol, Calif., uses and sells EcoForms, containers made from grain husks -- primarily rice hulls -- and starch-based, water-soluble binders and biodegradable additives. Heat and pressure cement the ingredients to produce EcoForms, said Elise Loveday-Brown, cofounder of EcoForms and Sweetwater Nursery.

The pots are available in a grower series and a dressier pot for retailers.

EcoForms are suitable for all climates, all environments and all applications where plastic, clay or wooden containers are used, she said. They’re designed to last 5 years under normal use. They’re also resistant to freezing and thawing damage.

“EcoForms have excellent heat insulating characteristics, which results in outstanding root development,” she said.

Only after they have been discarded into a commercial or municipal landfill facility will decomposition take place. They then break down into nutrient-rich organic matter with a pH value of 7.0.

The Grower Series features standard pots in multiple sizes, each with corresponding shuttle-tray options. The grower pots are compatible with most commercial pot handling and watering systems, including tidal ebb-and-flow systems.

Paper and poo

Western Pulp features a molded-fiber nursery pot that is biodegradable and made from 100-percent recycled paper.

The ability to biodegrade is a “valuable benefit” because the containers can be planted “pot and all,” said Jim Lee, marketing and sales manager at Western Pulp.

The containers retain moisture better, said David Fredriks, president of Fredriks Nursery in Ripon, Calif. Fredriks switched from plastic to the fiber container about eight years ago.

Ball Seed offers the EasyScape program, which includes Ellepots that can be planted directly in the ground. The pots are made from degradable, nonwoven paper. The pots are prefilled with media and an initial nutrient charge of Daniels Professional Plant Food. The pots work well for perennials such as hibiscus, salvia, coreopsis and lobelia.

CowPots are biodegradable planters from a dairy farm in Colebrook, Conn. The pots are made from dairy cow manure.

Brothers Matt and Ben Freund are second-generation dairy farmers who continuously run a methane digester where raw manure from the cows is heated and stored in a large tank. The methane gas is collected and burned. At the end of this process the solids are separated from the liquid. The liquid goes back to the field to grow next year’s crops, which feed the cows. The solids continue composting. The composted manure that is weed-seed free is used to mold CowPots.

CowPots help to avoid plant stress and encourage root development, said Amy Gardner, marketing manager at CowPots.

Plastic processes

There are millions of plastic nursery containers in use. But they don’t all have to be relegated to the back of the property or to the landfill. Plastic can be recycled and reused.

Johnson Farms in Deerfield, N.J., recycled 125 tons of ag plastics in 2006, including pots and poly.

Keith MacIndoe, general manager at Johnson Farms, also is vice president of New Jersey Nursery and Landscape Association (NJNLA).

“NJNLA wanted to promote recycling as a key part of the green industry, instead of dumping this poly and plastic in landfills,” MacIndoe said. “I knew there had to be a better way.”

He found a recycler in Maryland that paid him for the plastic. The nursery pots don’t have to be rinsed, just have the dirt knocked off of them. The recycler sends a tractor-trailer to the farm to pick up the plastic. Johnson Farms uses a Tiger baler to remove the poly from the hoop houses.

Some containers can be sterilized and reused, although check with the manufacturer to verify the plastic won’t melt during treatment, said Jim Robbins, extension specialist at University of Arkansas.

For heat sterilization, use 174°F water for at least 10 seconds or steam at 199°F for 1 minute, he said. Chemical treatments include quaternary ammonium chloride salts, hydrogen dioxide, chlorine dioxide and chlorine bleach. Bleach shortens the pot’s shelflife and is easily deactivated by organic matter, Robbins said. Make sure most of the solid debris is removed from the pot before dipping, he said.

For more: William Evans, Fertil USA, (610) 767-9221; www.fertilusa.com. Carlton Plants, (800) 398-8733; www.carltonplants.com. Jiffy Products of America, (419) 660-1177; www.jiffypot.com. EcoForms, (707) 82-1577; www.ecoforms.com. Western Pulp, (800) 547-3407; www.westernpulp.com. Fredriks Nursery, (209) 599-2900; www.fredriksnursery.com. Ball Seed, (800) 879-2255; www.ballseed.com. CowPots, (860) 238-7687; www.cowpots.com. Johnson Farms, (856) 358-1123; www.johnsonfarmsinc.com. Jim Robbins, University of Arkansas, (501) 671-2307; jrobbins@uaex.edu.

- Kelli Rodda

March 2008

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Researchers are touting the benefits of poultry feathers as an alternative to some plastic products, including nursery containers. For the last two years, the Horticultural Research Institute (HRI) has been working with USDA Agricultural Research Service to bring a biodegradable pot to the industry.

The U.S. poultry industry generates more than 5 billion pounds of feather waste each year. Instead of going to a landfill, it can provide a clean source of the protein keratin. The feather keratin can be formed into value-added products such as mats, filters, composites and polymers.

Keratin obtained from poultry feather waste can be the feedstock for manufacture of lightweight and durable materials, said Marc Teffeau, director of research and regulatory affairs at HRI. And the keratin obtained from feathers is considered sustainable.

HRI has initially invested $100,000 for three years to support this research effort. The three-year CRADA focuses on development of the technology and manufacturing process to develop biodegradable nursery pots that can be recycled or composted after the plants

Biodegradable pots will help improve growers’ profit margins as the cost of pots made from petroleum resins rises.

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“Growing plants in biodegradable containers that can be composted by the end user or at landfill sites is a logical extension of our sustainable emphasis,” Teffeau said.

- Marc Teffeau

For more: Marc Teffeau, HRI, (202) 789-2900; mteffeau@anla.org.

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Fiber, plastic benefits depend on 2 fundamental cycles

When it comes to choosing environmentally friendly pots we typically think it’s the same question we face at the supermarket checkout. Namely, paper (fiber) or plastic?

Really, this is a false question. Both can be good environmental choices. It all depends on what you make the pot from and what happens to it at the end of its useful service life.

In principle there are two fundamental cycles we can design any product to work in:

1. The biological cycle.

2. The technical cycle.

As gardeners and growers, we’re well used to the former. We know plant material can be decomposed and safely returned to the soil as nutrients -- as long as we have not contaminated the compostable material with any persistent, bioaccumulative or toxic substances along the way.

In this way, fiber pots of all sorts can be considered good environmental choices. They follow the “Cradle to Cradle” principle of Waste = Food. Effectively there is no waste because the pot is reused as food in the biological cycle.

But plastic also can be a good environmental option. The input raw materials may be assessed for human and environmental health and can be recycled after their initial use. Such pots could qualify for a third-party certification program like that offered by MBDC.

When we think and design with “technical nutrients” in mind we use nature as a model and mentor. We intentionally design for safe cycling with reutilization of the plastic at the end of the service life designed in at the outset.

If you’re a retailer or retail grower, why not invite your customers back to your store by collecting these “technical nutrients”? By acting as a valuable collecting point for recycling you get your customer back. When you build this into your business model we call the pot a “product of service.” The customer didn’t buy the plastic molecules of the pot when you sold the plant in a container. You only sold the service of the plastic container as a convenient means to get the plant home in good condition.

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You expect to get the plastic back as a valuable technical nutrient to be used over and over. Who wants to build a coalition of companies dedicated to closing the loop on plastic pot materials?

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Recycling program saves containers from Missouri landfills

Last year, the Missouri Botanical Garden recycled more than 100,000 pounds of horticultural plastic originally destined for landfills. The recycling program has collected more than 300 tons of waste during the last decade.

Four years ago, the program expanded to include collections from wholesale growers and landscape contractors.

Pots and trays are transformed into plastic landscaping timbers and retaining wall ties.

“It is increasingly apparent that our disregard for the reuse of plant containers ends in millions of pounds of plastic being wasted into landfills each year,” said Steve Cline, manager of the Kemper Center for Home Gardening and recycling program founder. “Providing an alternative to pitching pots by offering a program to recycle them has sparked a sense of loyalty to doing the right thing. We continue to be impressed with the public and green-industry response to this effort.”

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This year the garden plans to expand the fleet of recycling trailers to additional nurseries and garden centers, and make the satellite collections available year-round.

For more: Missouri Botanical Garden, (314) 577-9561; www.mobot.org.

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Technical nutrient: A material that remains in a closed-loop system of manufacture, reuse and recovery (the technical metabolism), maintaining its value through many product life cycles.

Waste equals food: A design strategy where all materials are viewed as continuously valuable, circulating in closed loops of production, use and recycling.

Product of service: A product that is used by the customer, formally or in effect, but owned by the manufacturer. The manufacturer maintains ownership of valuable material assets for continual reuse while the customer receives the service of the product without assuming its material liability. Products that can utilize valuable but potentially hazardous materials can be optimized as products of service.

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Design chemistry: The incorporation of scientific and ecological knowledge into product and process design.

Source: MBDC.

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