Biodiversity in Governors Island: Andi Pettis Is Bringing Biodiversity Back at the Urban Island

This is part of a series with Perfect Earth Project, a nonprofit dedicated to toxic-free, nature-based gardening, on how you can be more sustainable in your landscapes at home. 

“We have declared 2024 the year of milkweed,” says Andi Pettis, director of horticulture at Governors Island. For the past couple of years, Pettis and her team have been busy incorporating milkweed into the island’s plantings. They’re focusing on the three species native to the ecoregion: butterfly weed (Pettis’s favorite because of the “incredible variation in color from golden yellow to almost scarlet”), mauvy common milkweed, and hot pink swamp milkweed. Her goal is to finish planting 5,000 milkweed plants this year. “Showing the relationship between monarch butterflies and milkweed is an easy way for us to connect people to the benefits of native plants and show them why it’s important to support wildlife even in an urban environment.” The efforts have paid off. They’ve been noticing more and more monarchs on the island. You’ve heard it before: If you plant it, they really do come. (See Monarch Butterflies Are Nearing Extinction: 5 Ways to Help.)

Planting milkweed is just one of the many initiatives that Pettis and her team are doing to bolster biodiversity. “Climate resiliency and sustainability were sort of baked into the design of the park,” she says. Created by the design firm West 8, with Mathews Nielson Landscape Architects, the park features 120 acres of hills, meadows, and forests in the middle of New York Harbor. “It was a reuse project really—an old military base turned into a public space with new parks,” she said. “But there was no horticulture staff when I was hired [six years ago].” Pettis, who trained at Brooklyn Botanic Garden and had risen through the ranks at The High Line to become director of horticulture before moving to Governors Island, had to build a team from scratch and began to rehabilitate areas where maintenance had been deferred for years. Today, she and her team have introduced 52 native plant species to the island, planted habitat for butterflies and birds, and brought in sheep to tame the rampant spread of invasive species. “We’re working with nature here,” she says. “It’s not a short fix, but it’s working. We’re in this for the long haul.”

Pettis talks about this bustling and beautiful urban island park and shares how they’re bringing biodiversity back. [This interview has been condensed and edited for clarity.]

Photography by Sarma Ozols, unless otherwise noted.

Q: How are you gardening for biodiversity?

A: The park was designed for sustainability and climate resilience. West 8 built hills and these kinds of swales and berms to raise part of the park out of the 100-year floodplain. Working with Matthews Nielsen, they created a lot of naturalistic areas based on coastal maritime plant communities and filled the park with a lot of native trees. I think there are 53 different species of native trees planted on the South Island alone! 

We have made it clear that we are choosing plants that mimic our coastal maritime shrublands and grasslands native plant communities. We’re also focusing on those that benefit biodiversity and wildlife. In areas where we have managed to retake the land with these native plant communities, we’ve seen huge upticks in the native insect populations.

Q: How are you adapting to our changing climate?

A: As temperatures warm, we are definitely experimenting with plants that would be considered more Southern. For example, we are considering planting live oaks on the island. We are also growing pawpaws, persimmons, and magnolias that are all doing really very well.