Mulch Appreciated

Contractors, wood processors and recyclers who can turn limbs, branches and wood debris into mulch can tap into a steady and healthy market.

The application of mulch to flower beds and gardens has soared in popularity for a variety of reasons having to do with aesthetics, the health of surrounding plants and the ability to stifle weeds.

Not all wood is suitable to be made into mulch, and some treated wood in particular is unwelcome in the mulch stream. But recyclers who can take the appropriate steps to produce commercially acceptable mulch have a product of value they can sell.

Property owners with space devoted to flower and shrubbery beds have increasingly designated the application of mulch a necessary step each spring.

The Mulch & Soil Council (MSC), Manassas, Va., on its Web site at www.mulchandsoilcouncil.org, offers a rationale for the use of mulch that seems to be accepted by most Americans: "Nothing neatens a yard more effectively than an attractive organic mulch spread on the bare soil under all trees and shrubs."

The council also cites horticultural reasons. In hot summer zones, "Heat and drought stress most plants," and in areas where watering restrictions have been declared, rescuing those plants can be problematic. Surrounding plants and flowers with mulch, however can "help retain soil moisture during the summer’s hottest and driest days" according to the council.

Demand for mulch has led to greater production of the product, to the point where spot shortages sometimes occur in the market. The 2001 economic downturn that witnessed a decline in forestry, sawmill production and other industries whose byproducts are turned into mulch dried up the supply of mulch in the Northeast and the Mid-Atlantic. At that same time, biomass power plants were beginning to go online in the Northeast, creating a strain on the demand side as well.

Such conditions are currently in play on the West Coast, according to Mark Lyman, president of West Salem Machinery, Salem, Ore. Lyman’s company supplies grinders and other equipment used by recyclers and woodworking companies, sometimes in the production of mulch.

The housing slowdown has hit parts of the West Coast hard, creating a slowdown in sawmill, lumber yard and timbering activities. This has caused a reduction of potential material to produce mulch on the supply side.

On the demand side, government grants as well as private investment has made alternative fuels—including biomass—a hot market. Increased demand for wood-based fuels has caused new buyers to be in the market for a smaller overall stream of wood byproducts.

"Here in the Northwest, boiler fuel prices have gone up, particle board furnish pricing has gone up, as has the cost of mulch," says Lyman.

In the East the supply strains are not as great, says Bob Schanz, supply chain director of mulch producer and distributor Garick Inc., Cleveland.

But demand is robust enough that Schanz says he is continually looking for quality suppliers. "We have great supply partners, but we’re always looking for additional supply," he remarks. "We see ourselves as a potential customer for somebody who is grinding or reducing wood waste; we are a large purchaser of wood byproducts."

Adds Schanz, a 20-year industry veteran, "It has been a good, steady growth industry, and the demand for colored mulches in particular has increased over the years."

As with a host of secondary commodities that includes metals and plastics, a global hunger for raw materials could continue to boost the value of scrap wood and even land clearing debris.

Unless pricing causes consumers to turn away from mulch, the forecast is for a continued preference for the product.

A 2006 study by The Freedonia Group Inc., Cleveland, addresses only the bagged mulch market in the United States, not the larger market mulch measured by the cubic yard and used by landscapers, property managers and many property owners.

The research company predicts that the demand for bagged mulch will grow by an average of 5.5 percent per year between 2005 and 2010. Combined with a healthy growth in demand in the first half of this decade, that would mean the sale of bagged mulch and soils will zoom from $530 million in 2000 to $915 million in 2010.

"Home gardening activity, including lawn care, has been steadily increasing over the past decade as the baby boom generation has entered the 55-to-64-year-old age segment—the demographic that is most likely to be or become gardeners," reports The Freedonia Group.

The Mulch & Soil Council was originally known as the National Bark Producers Association, reflecting the widespread presence of tree bark as a leading source material for mulch.

By the late 1990s, however, a name change had taken place, with the current name (featuring the words mulch and soil rather than bark) chosen in part to "recognize the variety of quality products available in the current horticultural mulch market," according to the MSC.

While the MSC recognizes that mulch can be produced from materials beyond tree bark, it has also expressed concerns about potential contamination in the mulch stream that can occur when scrap wood is used to produce mulch.

Its statement on scrap wood treated with chromated copper arsenate (CCA) reads in part, "The Council supports and encourages wood recycling as an environmentally friendly practice when it is done correctly. However, removal of all CCA-treated wood and other potential contaminants must be a required part of responsible wood recycling."

Says Schanz, "Any of the wood that’s been treated or has had chemicals on it from paint or preservatives" is not suitable.

Recyclers, including those represented by the Construction Materials Recycling Association (CMRA), have been working to ensure that CCA-treated wood can be identified and handled appropriately when it enters a recycling facility.

The CMRA has called upon researchers at the University of Florida to help analyze the potential dangers of CCA-treated wood, as well as to help recyclers best identify CCA-treated wood when it enters their facilities. (See, "Warning Signs," pgs. 24-32 of the Sept./Oct. 2005 edition of C&DR, or on the Web at www.CDRecycler.com)

A University of Florida research team worked with Florida Wood Recycling, Medley, Fla., to determine the effectiveness of inspection and separation methods, including the application of an identifying liquid stain and an X-ray fluorescence (XRF) analyzer.

The researchers deemed the XRF units as effective, but also noted that their use increased sort times "by up to 10-fold."

Lyman suggests that mixed C&D recyclers may be best off using a positive sort of clean wood to harvest material that can be processed into mulch. "I think, in a C&D operation, the ideal thing is to be positive-picking ‘Grade A’ wood to make mulch," says Lyman, "so you are basically getting an inspected piece of material at that point."

Although this method results in a smaller overall volume of mulch, "In a lot of cases, there is [still] enough material on these lines that you can put in a separate small grinder and process that material into a mulch product immediately."

The benefits, says Lyman, go beyond the production of an uncontaminated and consistent product. "That’s a huge reduction in material handling, labor, machine costs—there are tremendous benefits," he remarks. "At that point, you have a metered, controlled product. It’s a very cost-effective way to process and convert clean wood."

At Garick, Schanz says a combination of grinding and screening clean wood is preferred. "You can make it with just a grinder if you keep switching out screens, but often it can’t be done in one pass."

Typically, Lyman finds that the use of a disc screen can create a product that minimizes the appearance of larger, splintered wood pieces considered undesirable by mulch vendors and users.

On the other end of the size spectrum, a trommel screen can be best if eliminating fines is a concern. Mulch producers who colorize their product are often the keenest to eliminate excessive fines. "Some companies screen them out because they absorb a lot of colorant," says Lyman. "Plus, a lot of times there is a separate market of screened fines."

Those who can put in place best practices to make a good mulch product may be glad they have done so.

Recyclers who ensure that contaminants stay out of their mulch and who can get access to usable feedstock may encounter a higher-priced market for mulch if the alternative energy markets remain as heated as they have been in the past two years.