Elevated profits

As in any business, the ability to specialize paves the way for greater potential sales. Just like doctors can focus their practices in areas like optometry or pediatrics to provide advanced care, plant producers can concentrate in a specific crop (or types of crops) to set themselves apart as experts in the field.

Ed Snodgrass, the fifth-generation president of Emory Knoll Farms in Street, Md., considered this idea heavily as he saw fewer opportunities to become more profitable in his 140-year-old grain crop business.

“I got kind of disillusioned with the American small farm experience from a number of perspectives,” Snodgrass says. “One was economics. There really wasn’t much of a living in it. And that makes a difference.” The other, he says, was ecological. With consumers trending toward organic, he’d have to let his land go fallow for five to seven years while it rid itself of the chemicals he previously used if he wanted to go that route.

“Those were really unacceptable business conditions for me,” he says. “So I thought, ‘Well, I wonder if there’s a way to think about the property in a different way.’”

During a search in the Washington, D.C. area for new crops to grow in the late ‘90s, Snodgrass came across a landscape architect who told him he needed plants for green roofs.

When Snodgrass spoke to the landscape architect, he wasn’t exactly sure what a green roof was. He later found that a green roof is an installation of plants on a rooftop that provides stormwater management, has the potential to attract pollinators and other types of biodiversity, and boasts aesthetic value, especially in urban areas. After conducting more research on its numerous potential benefits to urban areas, as well as his own business, he decided to convert his entire operation to growing ideal plants for green roof installations.

Now, Emory Knoll Farms, also known as “Green Roof Plants,” has provided plant material for more than 1,500 projects (more than 180 acres of rooftop space) across the U.S. Some of his most notable green roofs include the Library of Congress Audio and Film Archive, Interior of Agriculture, World Wildlife Fund and American Association of Landscape Architects.

Trickle down of benefits

The idea that highly populated cities need to continually strive to add greenery back into their ecosystems isn’t a new one.

“Most of the cities in the U.S. were the nicest places to live before we built cities on them,” Snodgrass says. “They were the intersection of the forest and waterways and estuaries.

“Frankly, that’s why people chose them. So when you take all that away, when you put water through pipes and make land into roads and concrete and buildings, you’re dramatically changing how water moves through those areas, and that’s a big problem,” he adds.

When a city is looking to add plants back into area, they can turn to park lands, athletic fields and streets were trees could be planted. The next available spaces are rooftops. After all, cities often contain thousands and thousands of square footage of rooftop space.

Not only can green roofs positively impact water movement throughout a city, Snodgrass says, but they can also change the thermal performance of a building into one with higher efficiency. The plants keep the structure cooler. Additionally, you can create new habitats by providing a place for insects and birds to thrive.

“The green roofs are part of a new trend in horticulture that’s [centered] around biological engineering, and not ornamental horticulture,” Snodgrass says.

Picking the best plants

While creating biodiverse environments on rooftops has plenty of benefits for the building owner and community as a whole, it won’t work without the right plants. Rooftops require varieties primed to last in relatively low-maintenance rooftop conditions.

Mostly, the plant selection depends on the geographic region in which the roof is located. Hardy succulent sedums are a top-tier pick, as they require low fertility and not very much water, Snodgrass says. Some examples include Sedum spurium, S. middendorfianum and S. montanum ssp. orientale. Other wildlife-type plants including allium, echinacea, rudbeckia and phlox can also work well, according to greenroofs.com, an industry hub for all topics related to living roofs. Even some drought-tolerant grasses, like andropogon or panicum can also thrive on rooftops, the site reports.

The conditions on a rooftop are harsh, Snodgrass says, so green roofs need to be able to withstand all the direct sunlight and lack of care the plants will receive in a gravel-based media about 3-4 inches deep.

And to plant for greater success, Snodgrass recommends a successional approach. “They’re not really like a garden design where you say, ‘I’m going to put in a perennial border. Then I’m going to have someone maintain the integrity of that design,’” he says. Instead, it’s OK if one group of plants is performing better at the time installation, and another group of plants becomes more dominant after time passes.

But, when wind erosion or noxious weeds roll in, you’ll need to find a plan for replanting. Or, depending on the specific roof’s criteria – for instance the expectation is that the roof must be 85 percent vegetative in two years – some or all of it may need to be replanted. However, even if a small area of plants dies off for one reason or another, the rooftop can still handle the stormwater because most of the work is being done by the media, Snodgrass explains. It will still be functional.

However, he notes that in the U.S., we care a little bit more about a green roof’s appearance than those in Europe or other areas of the world. There, the function of the green roof outweighs aesthetic value.

Another benefit of the green roof is the lack of pest pressure.

“There’s not a lot of harmful insect life up there,” Snodgrass says. “Things like aphids won’t be up there because there’s too much wind.” Plus, because of the access to direct sunlight and wind, the chance of constant humidity and dampness also decreases on a rooftop.

Customize, don’t add on

Snodgrass says that although green roof plants are relatively easy to grow, annual or perennial growers should take caution when deciding to take on these varieties in their operations.

“Most commercial nurseries push product pretty hard with water and fertility – so the tissue is a little soft for a green roof,” he says.

The plants need to be hardened off before they’re sent to the client to be suitable for an environment of neglect, he adds.

“You don’t want that call that says, ‘Hey, all these plants you supplied us, they’re mostly dead,’” he says, adding that while they could be the correct genus and species, they still have to be grown the right way. If growers are to produce green roof plants, they’ll also need to be ready to take on some additional responsibilities as it relates to sales. Snodgrass’ job requires him to take on many roles – and most of the time, it is “consultant.”

He says that as a green roof specialist, he spends a lot more time on the phone with customers compared to wholesale nurseries.

“It’s not an order-fulfillment world,” Snodgrass says.

Customers are usually installers, designers and maintenance staff who don’t necessarily have a plant background.

“It’s emerging technology, so there’s a lot of handholding horticulturally,” he says. Snodgrass finds himself teaching roofers or architects about which plants will work well, based on criteria like sun and shade of the building, and examining more subjective aspects like, “Is the company CEO’s window overlooking the roof?”

The final destination

Once plants are ready to ship, the sales transaction doesn’t end there. There’s even more planning to make sure product is delivered at the right time, in the right condition for installation.

There’s considerable checking and re-checking on all the moving parts of green roof plants delivery, including construction delays – or acquiring proper ID if you’re working on a federally secure facility, for example.

Packaging that plants are shipped in must also be different, Snodgrass says, because the plants will likely be lifted with a crane, possibly 30 to 40 stories high. Growers will want to ensure plants can be secured to lower the risk of them falling off of the lift.

Timing of the delivery is also key, because crane time can cost hundreds of dollars an hour, he adds, in addition to the highly skilled labor that’s being paid by the hour for the job.

In case anything goes wrong on a green roof project, “You can’t have your customer bleed cash like that,” he says. “So, we have to have delivery mechanisms that fit with the construction world, and not the landscape world.”

Picking the best people

Learning this new market for the past 15-plus years has been exciting for Snodgrass, but perhaps one of the most rewarding aspects is the interest he’s garnered from his employees. Though Emory Knolls’ staff is small, Snodgrass says he’s never had trouble acquiring labor for his work in the green roofs market.

“You get people who are enthusiastic about where your plants end up, so it’s not [as much] of a grind,” he says. He currently has an intern from the University of Melbourne in Australia working toward an urban horticulture degree, as well as two other young employees who, at press time, were studying abroad to increase their horticultural knowledge base.

“I would trust them with anything. I mean, they’re just great,” he says. “They innovate, and you get more than just compliance. You get the next level of service out of them.”

Snodgrass says he recently spent two months in Australia and China, and he couldn’t have left the business in their hands unless they were truly capable.

A worldwide impact

Snodgrass’ travels are geared toward helping to teach others about how to build green roofs. He also consults for a Chinese green roof company that’s looking into how to implement green roofs in different regions of the country, as China makes more effort to become environmentally sustainable. Snodgrass has taught the staff how to propagate, and he’s also met with local officials and mayors to move the public policy forward to make green roof installations smoother. He’s done similar work for regions in Australia and New Zealand.

Snodgrass has also co-written three books on the topic: one about which plants to use for green roofs, another about green roofs and public policy, and one about how to construct smaller, DIY green roofs. His publications can be found at amzn.to/2bi9zJK.