Greening the Landscape - Stategies for Environmentally Sound Practice
by Adam Regn Arvidson
CASE STUDY: MIDWEST GROUNDCOVERS (March 2011)
Midwest Groundcovers (MG) produces about 12 million plants each year on 120 acres west of Chicago. It grows shrubs and perennials, including forty varieties of sedum aimed at the green-roof market, native plants for the "American Beauties" program of the National Wildlife Federation, and planting modules for green-roof installations. The company is the labor of love of Peter Orum, a native Dane who has brought some Scandinavian sustainability to the Midwest. Orum started the company in the early 1980's and it now employs around two hundred seasonal employees and fifty year-round staff.
MG previously occupied a site in the Chicago suburb of St. Charles, Illinois. The company was outgrowing that space, and a fortuitous buyout of part of its property for a highway project facilitated a move to the current site in more rural Virgil. The company has employed sustainable practices since its inception, like reusing plastic containers, but the new site offered the chance to rethink the entire way the business is organized.
The landscape architect Chris Lannert, who founded the Lannert Group, has known Orum for thirty years; they met on a small landscaping job early in Lannert’s career. In 2001, Orum hired Lannert to master plan their new container nursery and corporate headquarters. The landscape architect immediately recognized the potential to make the company's production more efficient. "This is really an industrial process," describes Lannert, "but they don't make widgets, they make plants. When you machine a part and you a scrap metal, you don't just throw it away, you gather it up, you melt it back down, and you pour a new part. They could do the same thing with all of their nutrients, with all of their water."
That comprehensive reuse would be difficult across 120 acres, so the site is broken down into four growing areas, each ranging from between 25 to 30 acres. This is the genius of the design: each growing area (three are built) is self-contained. Each has its own shop, vehicles, water retention ponds, filtration and nutrification system, and employees. This cuts on-site vehicle miles roughly in half.
The planning and design process took five years, including a year of negotiation with Kane County to get a variance to place what is considered an industrial business in an agricultural area. That negotiation was helped by the fact that MG would install vegetated windbreaks, which also shield the site from view. The windbreaks cost money, but they help reduce water use by blocking desiccating winds and they protect seasonal greenhouses from damage.
Another major showpiece is the drainage, irrigation and fertilization system. Yes, that's one system - the three are inextricably linked at MG, something not often the case at nurseries. MG fertilizes primarily through its irrigation water, something it has done for twenty-five years. "Every drop of water that falls on the developed part of the property," explained Christa Orum-Keller, MG's vice president (who is also a registered landscape architect), "moves to detention basins and is used for irrigation." This is also true of the irrigation water itself. Essentially, each growing lot is made of free-draining aggregate, like that found under permeable pavement. Water moves downward into the aggregate and enters a perforated pipe, through which it makes its way to swales, then to large storage ponds.
Near each system of ponds (one for each growing area) is a highly complex pumping system. Water is drawn from the ponds and is tested for its nutrient content. Fertilizer is only added if necessary. Then the water is provided to the plants through aerial sprays or, sometimes, more expensive (but more efficient) drip irrigation. The whole site is graded, according to Lannert, to move water from the growing areas into the ponds then back to the growing areas in the form of irrigation.
According to Orum-Keller both water and fertilizer are resources that can be reclaimed, thereby saving money. She says that's not common practice: "I think a lot of small growers are just throwing fertilizer on the plants and not putting much science into it." She feels MG's system makes sense from both a cost and an environmental perspective. "Fertilizer is expensive," she stresses, "so if you're just throwing it out there because you think it might help, you're throwing money away. It's not a good thing to have more fertilizer in the water than you need." By reclaiming both water and fertilizer, Orum-Keller estimates that the company cuts its fertilizer use and cost in half.
In the center of the complex is a facility operated by a separated company, Midwest Trading (though MG and Midwest Trading share a board and owners). This company makes soil and mulch for conventional landscape applications and green roofs. MG piles all its green waste in a single location, and when the pile reaches a certain height, MG works with Midwest Trading to reuse it in some way. How the waste is used depends on the waste itself. Woody ornamentals might get chipped and turned into mulch. Diseased material can be ground up and put on a fallow field as an organic amendment - as long as no plants will grow there in the near future. Whatever happens to the green waste, all of it is reused somehow within the nursery operation.
In addition to its compact growing areas, drainage and irrigation system, and green waste recycling, MG allows customers to return plastic plant pots from any grower, which they bale on site, reducing the cost to have them recycled. It reuses some of these pots as is- simply knocking out the dirt and replanting. At its growing field in Michigan, all the plastic pots go to East Jordan Plastics, a pioneering company that is making new plant pots out of recycled plant pots (MG's Michigan site also buys recycled pots from East Jordan, closing the loop on its own plastic). MG reuses its white plastic greenhouse covers three times and then recycles them. And the company's "energy committee" is considering wind and solar power generation, electric site vehicles, and a new geothermal greenhouse for the fourth growing area. "At our old site", explains Orum-Keller, "[the elements of sustainability] were a little bit here and a little bit there." The new campus brings all of MG's environmental practices together in an integrated system.
Expert taken from Greening the Landscape - Strategies for Environmentally Sound Practice by Adam Regn Arvidson, Chapter 5: Water and Fertilizer: Water, Water Everywhere, pages 61-65, W. W. Norton & Company, Inc.