If you’ve ever planted a garden, or even one pumpkin seed, you know the excitement of seeing those first sprouts emerge. So imagine thousands of plants and flowers surfacing, expertly orchestrated to grow and bloom spring through fall to bring function and beauty to the Green & Main site. The Green & Main Pilot Project landscaping was installed this past October, so you can count on a burst of fresh greenery and flowers to greet spring.
Beginning the Installation Process
Just in the nick of time, the Green & Main site was ready for the grass and flower plugs to be installed. Under the design guidance of Zach Heitzman of Green Bean Landscapes in Ankeny, the task of strategically positioning the plants to support the site’s environmental and aesthetic goals began.
I talked to Zach on a chilly December day as he worked in his Ankeny office designing Green Bean’s landscaping projects for next spring.
“Really, the basic concept of the Green & Main’s landscaping had been sketched out for a long, long time by the Green & Main team” stated Zach. “My role was to incorporate landscaping into the site that would accommodate their stormwater management goals, including building a bioswale, meeting the LEED and SITES (the Sustainable Sites Initiative) requirements, and offering an aesthetically pleasing experience as well. It was all about creating the details around the vision.”
“Of course, the final design also had to be documented for the City of Des Moines’ approval to ensure it complied with their guidelines regarding ground elevation, easements and pavements,” concluded Zach.
Contaminated Soil Amended to Make Ready for Our Plants
Before a single seed was planted, the soil at the site needed to be amended.
“Since the ground had been used for many, many purposes over a hundred or so years,” Zach noted, “we assumed that it would be contaminated with impurities. So the first step was to amend the soil. As required by SITES, we documented the before-and-after health of the soil. Prior to amending it, we took samples of the existing soil and sent it to the USDA where they evaluate the nutrients, the permeability and the organic matter. Then we sent a sample of the amended soil. We also sent samples to Iowa State to test the organic matter. Before-and-after test results have yet to come back.”
The method used by Zach for amending the soil was one that was recommended by the Iowa Department of Agriculture and Land Stewardship. This method included using a mini excavator to tear up 24 inches of the site’s topsoil to make it less compacted. Prior to this, two inches of compost were placed on top of the ground in order to be incorporated into the existing soil. The affect is a significant increase of organic matter and nutrients in the soil. Also, by making the soil more permeable and nutrient-rich, we now have soil that absorbs stormwater much more aggressively.
The compost used on the Green & Main site was acquired from Des Moines Metro Waste Authority and consists of leaves, sticks, and grass clippings that were collected from Des Moines residents and businesses.
How SITES and LEED Requirements Affect the Landscaping Design
Zach designed the strategic placement of shade trees in the landscaping in order to decrease the heat inside the building. According to the EPA, trees and vegetation lower surface and air temperatures by providing shade as well as through evapotranspiration, the process of transporting water into the atmosphere. Shaded surfaces, for example, may be 20–45°F cooler than the peak temperatures of unshaded materials, which then decreases demand for air conditioning.
Using plants that are more adaptive to our climate will thrive without a lot of extra fertilizing and watering. Once these types of plants are well established, they are pretty self-sufficient.
The type of vegetation incorporated in the Green & Main landscaping was selected specifically for its ability to absorb more water via root systems and soil. Vegetation reduces runoff and improves water quality by absorbing and filtering rainwater.
A small bioswale was also built by Zach Heitzman to affect stormwater management goals. “This was one of my more challenging projects at the Green & Main site,” added Zach. “Essentially I had to create the bioswale by hand. It was too hard to bring in machinery to dig and form the bioswale, so I came in with a rake, shovel and wheelbarrow. More challenging was keeping the construction crew away from it! Of course, there were a lot of people on site and once we graded and shaped the bioswale, we couldn’t have people walking over it.”
“Overall, I’d say that the vegetation on the site is more functional than aesthetic,” concludes Zach. “[But] it will definitely be beautiful, from spring through the fall.”
Kelly Hayes of Allendan Seed…and Her Forbs
Allendan Seed of Winterset is one of the largest producers of native prairie grass and wildflower seeds in the United States. Allendan Seed produces over 250 species of native grass and wildflowers. Dan and Sonia Allen began farming conventional row crops in 1976. Today they are still a family operation. Their four children migrated home to farm upon graduating from Iowa State University.
Daughter Kelly Allen Hayes is Allandan’s production manager. She oversees the greenhouses and fields, planting about two million seeds a year, overseeing all production from plugs to harvest on the company’s 40 acres.
“Forbs” are technically defined as herbaceous flowering plants, wildflowers being a type of forb. Kelly Hayes can assure us thousands of these little beauties will poke up through the ground at the Green & Main site come next spring.
“Once I had become familiar with the Green & Main site itself and the objectives of the initiative, I chose over 30 species of plants, grasses and forbs to incorporate into the landscaping,” said Kelly. “I focused on species with root systems that would be beneficial to the ecosystem, aiding with stormwater absorption and water conservation. But I also added some visually appealing colors, heights and textures to the site that will appear from spring to fall.”
Some of the species planted by Kelly are prairie violets, prairie smoke, prairie blazingstar, prairie dropseed, little bluestem, blue lobelia, rattlesnake master, New England aster and silky aster. Butterfly milkweed was placed all along the bioswale. The plants and flowers range from four-inches to seven-feet tall. “I also incorporated some mountain mint into the landscape,” continued Kelly. “Mountain mint really aids in erosion control because it forms runners, essentially a type of living carpet after a few years of growth.”
Personal Touches to the Landscaping
The designer’s creativity plays a part in any landscaping project, and Zach Heitzman’s creative contribution to the site can be found in every foot of the landscaping. However, in talking with him, he says his most significant personal contribution to the design is in the limestone incorporated into the landscaping.
“One of my favorite parts of operating my own business is that I can create my own designs in some of the detailed elements,” explained Zach. “The limestone pieces that I worked with were acquired from an Anamosa quarry – all limestone in Iowa comes from the Anamosa area – and they are a rich cream color that really complements the site. The pieces of limestone are raw and broken, so I created natural-looking outcroppings among the plants and placed some of the stone in an informal path that suggests native limestone outcroppings.
“I’m proud of that stonework on the site,” continued Zach. “But I’m mostly proud of how we all worked together to make the final landscaping a success. We got it done to specifications within a very tight timeframe. Everyone really contributed their talents to the project and that collaboration resulted in success”
Asked what he would do differently if he had more space to work with, Zach responded that he’d love to have the additional space to incorporate more educational opportunities. “I would really like for people to be able to walk through guided pathways with signage explaining the plant species and how they specifically benefit the environment. I would use the very same technologies that I used on the Green & Main site; I’d just make it a more dramatic experience for visitors.”
A big “thank you” to both Zach and Kelly for the colorful flowers and vegetation coming up next spring. I, for one, am looking forward to it.
–Ann Wilde is a Des Moines marketing strategist and writer who also has a special interest in preserving and creating sustainable communities.