From the ground up
|By Katie Navarra|
Focusing on soil health gives landscapes the right foundation to thrive.
A building’s foundation determines how sturdy the structure will be. The same philosophy applies to the soil that supports a landscape. Plants, trees and turf are more resilient and require less care with good soil health. Rob Boyker, owner of Seattle-based Avid Landscape, Design and Development LLC, approaches every project from this point of view.
“I like the progressiveness of putting soil health first,” he says.
In a perfect world, landscape companies are included in the earliest phases of the project. The reality is that it’s not usually until after the fact when the phone rings.
“Getting in on the design process early allows us to take a more holistic approach,” he says. “Then we can assess the topography and hydrology, how the drainage and tree roots move water across the area.”
Whether Boyker gets a call early or late in the process, he always starts with soil health. The approach is one he learned serving in the Peace Corps in West Africa. Working in forestry and agriculture, the goal was to teach people how to use cover crops and how to make manure tea and compost. In that region the practices were implemented out of necessity rather than because they were focused on environmentalism. The bonus is that the practices are sustainable.
One practice that Boyker uses in his work is permaculture design, a philosophy that focuses on working with nature to develop stronger, more healthy landscapes. By looking at all systems on a site, the considerations are for how each of them will work together to benefit all life forms. In landscaping, it combines conceptual, material and strategic components into the planning phase.
Even in the Pacific Northwest where there is a great emphasis on sustainability and environmentalism, selling soil health is still a challenge. Landscaping is still considered a commodity. Price and picture-perfect results often take precedence. And it is a slow process to change people’s minds. Sticking to the company’s values and educating the client is an important part of the process.
That approach has landed Boyker the client relationships that have allowed him to implement soil health strategies even when the customer may not buy in 100%. Here he shares a behind-the-scenes look at how he puts soil first.
On the job
When Boyker is called into a job, his first step is observation. He looks at the topography and where water naturally flows through the site. On properties with vegetation, he looks for weeds that are indicator species for soil health problems. For example, dandelions are an indicator species of compact or acidic soil. Clover suggests the soil is low in nitrogen. Wood sorrel points to acidic or heavy clay, and crabgrass indicates the soil has poor drainage.
“Right when I’m getting to a site, I look to see what is growing there because it is a good indication of underlying conditions,” he says.
Site contractors frequently park large equipment and vehicles on areas that are to become planting beds or lawns. Much of the native soil profile is disturbed through excavation, and soil compaction becomes a significant issue.
“Having multiple trades on and off the site each day is one of the biggest obstacles in this type of landscape renovation on a larger project like home construction,” he says. “The process of soil preparation is undervalued and hard to recognize.”
It can be easy to accidentally jeopardize the process of developing or prepared soil by washing out paintbrushes, parking vehicles or staging materials, for example.
This was precisely the case at a recent residential project. The ground was highly compacted with multiple contractors on-site daily. The seller had incorporated a generous landscape budget, but she wasn’t motivated by the long-term benefits soil health offered beyond the sale. The property had 7,000 square feet split between two areas and ample planting beds. The project also included hardscaping, irrigation and lighting.
“We do what we can for our reputation, and she gave us enough license in the design to use soil amendments even though she was indifferent about promoting long-term soil health,” he says.
When Boyker arrived on-site, his first step was taking a soil sample. The results weren’t surprising. The soils were typical Northwest soils, a composition that naturally supports a wide range of plants with little more than an annual (or biennial) application of organic material, such as compost, according to Boyker. The challenge for this project was that the excavation for the home addition and remodel mixed the soil profile and compacted the site.
“Each horizon in a soil profile has a distinct characteristic and role. Disturbing this profile is detrimental to the soil’s ability to perform its function,” he explains. “In a rainy locale like Seattle, this is extremely important with regard to site drainage, erosion and runoff. Compacted soil and disturbed soil profiles lose their capacity to play their essential role in the hydrological cycle.”
On new construction and development projects, the top and surface layers of topsoil are excavated and hauled off-site. That leaves landscape contractors the subsoil or substratum to work with. In these cases, the soil profile needs to be reconstructed. This process involves mixing in larger amounts of organic materials or compost to an average depth of 2 feet, according to Boyker. That is followed by the addition of up to 4 inches of topsoil mixed to a depth of 6 inches.
“Fortunately, with sustainable practices becoming more common, topsoil is stockpiled on development sites,” he says. “The soil is reused on the same site, reducing the carbon footprint of trucking, but the matter of repairing the profile and compaction still exists.”
Boyker estimates that on about 80% of commercial projects he has the opportunity to start from scratch. As part of the rebuilding process of lawns, he prefers seed. Sod is great for instant gratification, plus in the Seattle area it can be laid year-round, whereas seed is seasonal and relies on additional care and protection until it is established.
“One of the downsides to sod is that it comes with soil,” he says. “This is a small amount of soil, but if it is clay-heavy soil, it can create an interface between the sod and the soil that we have prepared for the lawn area. And an additional preference is to use alternative ‘eco-lawn’ seed mixtures.”
That was not the scenario on the home construction project mentioned earlier. There wasn’t the opportunity to start the turf areas from scratch. After evaluating the soil core samples, pH tests and site topography, an organic treatment program was applied.
They did have more influence in the planting beds. After loosening the compacted soil, they mixed in about 25 yards of fish compost on the site. The company favors fish compost because it is high in organic matter and is effective at building soil nutrients. A local supplier provides easy access to bagged and bulk products.
Once the plants were in, 4 inches of arborist chips were applied as mulch. The arborist chips are simply a byproduct of the work performed by local tree service companies. The raw product is dye-free.
Though the chips don’t provide additional nutrients to the soil they have proved highly effective at weed suppression.
“Traditionally, arborist chips are not considered as aesthetically appealing as dark or even red bark mulch, but it is a long-lasting organic layer,” he says. “A benefit is that the chips are a little rougher so when there is leaf droppage or a twig that would make other mulches look messy, it doesn’t look messy on the chips.”
In the long run, prioritizing soil health reduces the cost of landscape maintenance and plant water requirements. However, it’s a process that takes time and is more expensive upfront. In a market where customers are used to cheaper prices, Boyker works to convince customers that it’s worth the wait.
“We talk with all our clients one-on-one and try to give them a better understanding of how the science works and that we are not just trying to take more of their money,” he says. “I feel odd when I tell people I believe this as the truth for the future of our children but there are more benefits for everyone. It is finally a practice many companies in addition to ours are using.”
Boyker also encourages contractors interested in integrating soil health services to sign up for classes on permaculture and sustainable landscaping.
“A lot of what we do is still trial and error. We’re part of a statewide landscape association and are close with other members. We all have similar clients and so we chat and share info about our work,” he says.
A finished landscaping job with poor soil will look exactly like a finished project with healthy soil, at least for a few weeks. After that, when everyone is long gone, the poor soil installation will start flagging its deficiencies. At this point, the cause is often casually brushed off as being the fault of the new owners and their lack of having green thumbs.
“Failure in landscaping has become readily excusable for reasons that don’t always apply,” he says. “A properly planned and designed landscape with healthy soils and appropriate plant materials does not require human intervention to thrive.”
The author is a freelance writer in Mechanicville, New York, and can be reached at email@example.com.