management Horticultural Recycling — The Future Is Brighter

Pots, fl ats and other horticultural can be a challenge to recycle after being contaminated with soil and other organic material. But the options are expanding, and programs are cropping up in communities and garden centers all over the country to handle these products effi ciently and sustainably.

By Arthur Cameron GPN product news hanks to their lightweight, versatile there are issues related to sorting, are even cities that collect horticulture nature, plastics have found a multitude cleaning and disease control. Green- plastic curbside, a trend that would be T of uses in crop production and land- house coverings and fi lms great to see all over the country. Prices scaping. Around the world, millions of tons of cannot be reused because they dete- for recycled plastic are improving plastic are used each year to cover , riorate under UV radiation. Plus, after a drop last year, and there is more make containers and plug fl ats, and even mulch horticultural plastics get dirty. interest from the vegetable row crops. However, the fate of plastic Several different types of plastic companies to learn how to collect, in our environment is a serious issue. are used in the horticultural industry, sort, clean, grind and sell horticultural Our “green” industry has not always been including low-density , plastics. It seems to be getting easier to so green when it comes to reusing and recy- high-density polyethylene, and fi nd companies willing to partner with commu- cling the vast quantity of plastic generated. high-impact (see sidebar on page nity organizations for recycling events. Some Landfi lls are not an appropriate option, and 24). To maintain the highest quality of the recy- states, such as New Jersey, have developed pro- unless it’s stringently controlled, burning can cled product, these need to be carefully sorted grams to facilitate the collection of greenhouse release potentially dangerous compounds into and handled separately. And even when prop- plastics. Some professional horticulture groups, the atmosphere. Containers can be reused, but erly sorted, various contaminants including including the Minnesota Nursery & Landscape soil and organic matter reduce the quality of Association, have developed programs to col- recycled plastic compared to virgin material. lect plastic, and some retailers — both big boxes Every time plastic goes through the recycling and independent garden centers — have initi- process, contaminants and structural degrada- ated programs to collect and recycle plastic con- tion reduce the quality of the plastic, such that tainers and trays from gardeners. All of this is it may become more diffi cult to remanufacture good news. the same product. One of the most successful recycling pro- grams in the country for horticulture pots and The Good News trays was developed by Steve Cline at the Mis- The good news is that there seems to be souri Botanic Gardens. He has teamed with local an ever-expanding number of opportunities retailers and recyclers to develop a model pro- for recycling horticultural plastic. Not long gram that is the envy of everyone who’s seen it. ago, plastic was thrown into landfi lls or even There are several drop-off points in Greater St. Every time plastic goes through the recycling process, shipped away to places like China. Now, there Louis, and the collected plastic is transported contaminants reduce the quality of the resulting product.

20 GPN October 2009 www.gpnmag.com management The Best Container. OUR LOWEST PRICE.

to a single location for grinding. He has site storage until collection. been able to secure funding for collection Volunteer-staffed recycle drives are still bins specifi cally designed and labeled for an important means of collecting plastic horticultural plastic. At this time, Cline and directing it to appropriate recycling and his team are grinding all the plastic companies. These can be organized by together without sorting, and it is eventu- individuals, communities, growers and ally made into landscape timbers. They retail nurseries. They generally require even have their own grinder! According to large amounts of coordination and volun- the botanic garden’s website, the Plastic Pot teers, and they may require subsidization, Recycling program has saved more than depending on the amount of plastic col- 680,000 pounds (340 tons) of plastic garden lected, density of packing and distance to pots, cell packs and trays from landfi lls the recycler. At Michigan State University, since its inception. we’ve conducted two successful recycling drives and collected more than four tons of What You Can Do plastic. In Emmet County, Mich., a collec- Until we can generate revenues and sup- tion drive this spring collected nearly fi ve port for such facilities, the rest of us can do tons of plastic in four hours! There are many our best by identifying local recyclers and more successful examples. It is clear that working out collection mechanisms. Many the gardening public, greenhouse growers recycling companies require a minimum and landscapers are eager to divert more amount of plastic before pickup. This can plastic from landfi lls — it makes economic require growers to store plastic until they and environmental sense. They just need to have accumulated an adequate amount or be given the opportunity! that several growers band together and com- 1.0 GL Royale™ bine their plastic. Localized collection sites, Arthur Cameron is a professor of plant and 4.25" Grande™ preferably with capacity to bale and grind soil sciences at Michigan State University. He Self-Symetricize – our #1 Seller 4.50" Classic™ can be reached at [email protected] or (517) plastic, would be ideal. Some growers and Self-Symetricize retailers have purchased used semis for on- 355-5191, ext. 338.

It just got more affordable to sell faster. Proven Winners reduced the prices on branded containers and trays by 10 to 19%. Orders received by October 30, 2009 for immediate shipment will receive April 1, 2010 terms. For pricing and term details, visit https://shop.provenwinners.com/containerandtray or call 877-895-8138.

Nothing Sells Faster ®

Today, growers, garden centers, landscapers and home gardeners have more recycling/reuse options available for effi cient and sustainable plastics disposal. Write in 783 www.gpnmag.com October 2009 GPN 23 management

Plastics Used in Horticulture

High-Density Polyethylene Reusing and Recycling: HDPE- reduce the value of timber if not com- ware. Spun-bonded polypropylene Uses: HDPE is commonly used constructed plant containers can be pletely eliminated, growers may have (or woven polypropylene, trade- in nursery containers, specifi - reused, but it is best to sterilize them. to fi nd plastic recycling companies that marked as Tyvec) is used as row cally those used outdoors for trees Thielaviopsis black root rot spores can are willing to accept, wash and grind covers for frost protection, moisture and shrubs. Outside of , the persist in containers and infest subse- nursery containers. Recycled HDPE is barriers for buildings and disposable most important use for HDPE plastic is quent crops of susceptible species. typically not reformed into containers, -repellent clothing. for milk containers manufactured Still, some growers have reused con- but rather is made into plastic timber Reusing and Recycling: Reusing through the process of . tainers and have avoided problems to for landscaping, picnic tables and PP containers is possible but carries HDPE is also used to manufacture fuel date. Evergreen Acres Nursery near even railroad ties. Compared to wood, the same warnings as those for HDPE tanks for vehicles, various other screw- Spring Lake, Mich., reused 20,000 pots plastic lumber can be very heavy, but containers, specifi cally Thielaviopsis. top containers and some types of irri- that customers returned. They cleaned it’s becoming more popular each year. Virgin PP is white, whereas recycled gation pipes. HDPE resists breakage and sorted the used pots and potted PP will always be darker or even black and does not break down quickly up perennials that were not impacted Low-Density Polyethylene because of contaminants, which in under UV light. It is both thermally and by Thelaviopsis black root rot. Uses: LDPE, a relatively inexpen- some applications presents a barrier. chemically resistant and thus has been Major recycling of HDPE is typically sive plastic, is used extensively to Polypropylene is one of the more dif- extensively used for containing pesti- devoted to milk containers. Because cover greenhouses and has proven fi cult horticultural plastics to recycle, cides and . dirt and other contaminants can effective as a mulching material for though some recyclers will mix it with diverse food and ornamental crops HDPE to make landscape timber. such as strawberries, vegetables and even herbaceous perennial plants. It is High-Impact Polystyrene also commonly used for plastic bags. Uses: HIPS is commonly used for Clip-On Grower Trellis Reusing and Recycling: LDPE molding fl ats used for seedlings greenhouse fi lms cannot typically be and small plants. Pure solid polysty- reused. When used as a plastic mulch, rene is colorless, but plug trays are trapped soil greatly hampers recycling. generally black because they’re made into place Some plastic recycling companies from recycled plastic. These are inex- specialize in developing wash line sys- pensive and extremely lightweight. Snap tems for cleaning these plastics, and HIPS trays and liners are increasingly Just a wide range of specialized systems made from recycled plastic, and some have been developed. Still, washing is producers are displaying this informa- an extra cost and many plastic recy- tion directly on the trays. clers do not have this equipment, Reusing and Recycling: HIPS which reduces the number of options trays and liners are sometimes reused, • Clip the trellis onto available to growers. but more often they are discarded or the pot. When used as a greenhouse cover, recycled. Some growers can accu- • Twist the center LDPE fi lms break down from UV radia- mulate HIPS trays in large numbers support wire around tion, which limits its usefulness when when they purchase and transplant recycled. Unless baled, LDPE fi lm has young liners from a plug producer. the plant. a very low bulk density and is inef- HIPS trays are extremely light, diffi - • Carry your plants fi cient to transport. If at all possible, cult to compress and come in a mul- with little effort. bale LDPE fi lms before transporting. In titude of designs. Unless they are all some cases, recycling companies will of the same design, they do not stack provide the baling equipment for a lim- or nest. The trays may be clean, but ited amount of time when growers are the inserts are typically dirty. HIPS is removing fi eld mulch or greenhouse relatively easy to recycle in many parts Patented Design coverings. In the state of New Jersey, of the country. Some plastic recycling Sizes Available there is a statewide effort to aid nursery companies grind, melt and mold HIPS 1 gallon growers on the recycling of LDPE fi lms. directly back into trays, which elimi- In Michigan, there is a state-supported nates a step in the recycling process 2 gallon program to recycle LDPE plastic and enhances the fi nancial return. 3 gallon used to overwinter boats. This year, it Polystyrene is also used in caf- seems there are more opportunities for eteria trays, various cases and toys. Special orders are growers to recycle LDPE plastic. Expanded polystyrene, known as available with Sytrofoam, has long been used for minimum quantities. Polypropylene small plant containers. Expanded “We Support Your Plants” Uses: Polypropylene is com- polystyrene is generally more dif- monly used to construct plant fi cult to recycle and has a reputation Jenison • MI 49428 containers for greenhouse production for accumulating in the environment. ph(800)218-8210 of house plants, herbs, annuals, potted GPN fax(616)662-0887 DESIGNS fl owering plants and bedding plants. It www.rushcreekdesigns.com is generally durable, lightweight and LearnMore For more information resists breakage. PP also is used for related to this article, go to auto parts, food containers and dish- www.gpnmag.com/lm.cfm/gp100902 Write in 806

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