A historical rendering of the Garden State Parkway in New Jersey. The state's highways could soon look more like this, thanks to a law that requires all new plantings by transportation agencies to be native. Photo: Boston Public Library /Flickr CC (BY 2.0)

New Jersey may be dubbed the Garden State, but for many out-of-towners, it’s better known as a state full of asphalt and headaches, with its snarled parkways, smoggy turnpikes, and wallet-draining interstates.

But now, thanks to a trailblazing new law, thousands of miles of roadsides have the potential to be transformed into Jersey-fresh gardens. This month, the state government adopted a bill that requires the Department of Transportation and other transportation authorities to only use native plants to landscape roadways. The rule applies to any projects that break ground in and after late October.

It’s a niche (and neat) idea—one that was easy to sell, says Assemblyman David Wolfe (R), who helped draft and garner support for the bill with the main sponsor, State Senator James Holzapfel (R). “In the last year there’s been a lot more emphasis on native plants in the region,” Wolfe says. After Hurricane Sandy ravaged 94 percent of the Jersey coastline in 2012, residents began to realize how local flora play a role in preventing pollution, flooding, and erosion. “A lot of the people in the legislature have summer homes on the shore,” Holzapfel says, so they took the issue personally. Once a budget analysis showed that switching to native plants could save the state money, the decision was even easier.

The bill was largely the brainchild of the environmental nonprofit Save Barnegat Bay. The group, which is based in Toms River, New Jersey, has been at the forefront of the state’s clean-water movement since its founding in the 1970s. But recently, it’s devoted more energy to advocating for native plants as a tool to keep waterways pure.

The benefits of native plants are especially relevant for coastal conservation, Britta Wenzel, Save Barnegat Bay’s executive director, says. For example, when pesticides leak into stormwater runoff and end up in the ocean, they can lead to an explosion of algae. These “tides” choke oxygen supplies and kill marine wildlife, and sometimes cause health risks for beachgoers. But such hazards can be avoided with native plants, which reduce the need for pesticides and suck up extra nitrogen compounds from the environment. Plus, they’re better at holding soils together and withstanding rough wave action, and they foster entire ecosystems by supporting nesting and migrating birds, vital pollinators, and all sorts of insects.

Native plants can also make a highway less of a dead zone for wildlife. New Jersey has close to 3,352 miles of major state-controlled roads, despite having a landmass of only 7,300 square miles. But the roadsides are infested with invasive ornamentals such as Japanese barberry and multiflora rose. To make matters worse, cars are a major vehicle for the spread of invasive species: They pick up seeds with their tires and shuttle them over long distances. With natives lining the roads, there’s less chance for them to take root and co-opt the landscape.

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Save Barnegat Bay was inspired to write the new bill by a very specific highway. After Sandy damaged Route 35 in Bay Head, New Jersey, it was replanted with a species of salt-tolerant trees sourced from Asia. But the seedlings had to be sprinkled by watering trucks twice a week, and they eventually died. “It was like watching taxpayer money being thrown away, and it didn’t make environmental sense either,” Wenzel says. So, when the town proposed a new landscaping plan in 2014, Save Barnegat Bay decided to chime in. They hired a licensed architect and native-plants expert to draw up a detailed report of the vegetation along the route, highlighting which species would be better suited and more beneficial for the project.

It was this clearly presented scorecard that won local politicians over. “We needed to simply tell them what the problem was,” Save Barnegat Bay's Wenzel says. They were in awe of how inferior some of the oft-used exotic plants were compared to natives, she adds. “It was powerful."

In the end, Bay Head went with native plants for Route 35. And soon, with backing from Wolfe and other government officials, the local initiative grew into a statewide strategy. The idea of native wildlife struck a chord with the “Jersey Strong” spirit, Willie deCamp, Save Barnegat Bay’s president, says. Once the bill was introduced to the legislature, it received striking bipartisan support: The act sailed through the senate and assembly with a vote of 35-2 and 69-0, respectively, and was signed by Governor Chris Christie on May 1.

For Wenzel and deCamp, the law felt like an easy win. Now they’d like to see more folks join the native-plants movement. “It’s a concept that can be easily replicated,” deCamp says. Their advice to people looking to pass similar landscaping laws in their home states: Start by taking the steps required to save your own backyard to prove how the benefits can affect the greater good. Also, consider approaching the issue from a non-wildlife perspective. Native plants are vital for ecosystems, but when engaging legislators and community members, it might be better to try a different tact. “Politically, clean water is a better sell,” Will says. It depends on your locale, though: If you live in an area where hunting is a key, habitat conservation could be a better hook.

Wenzel also recommends avoiding the term “invasive,” as it can muddy up the discussion. “While working on the New Jersey legislation, we wanted to keep out of the debate of ‘what is an invasive,’ ” she says. Of course, looping in experts helps, too, whether they’re garden-club members, local botanists, or even industry folks such as foresters. The government is a big purchaser, Wenzel says, so a law would incentivize growers to put more native species on the market. State universities also make great partners, Assemblyman Wolfe points out; they can use their scientific data and educational reach to get the community talking about native plants.

Ultimately, the movement comes down to “grassroots dedication and selfless volunteers,” deCamp says. But until there’s a cause that ties it all together, the endeavor can be a real slog. “Change often comes about because of a specific trigger,” he notes. In New Jersey, it was a 24-mile stretch of highway. With a little luck and effort, other states shouldn't require a natural disaster to spark change, too.