What was once an overgrown patch of land at Custer Preserve has been transformed into a thriving native plant garden, the result of a three-year volunteer effort to restore habitat and demonstrate the benefits of native plants.
Now a certified Monarch Watch Waystation, the garden has become one of Southold’s most visible examples of how native plants support wildlife. It will be showcased on Thursday, July 23, during a Monarch Waystation Garden Tour & Talk from 4 to 6 p.m. at Southold Town’s Native Garden at Custer Preserve, hosted by ReWild North Fork, Group for the East End and the Southold Peconic Civic Association.
The eastern monarch butterfly population began a steep, sustained decline in the mid-1990s, according to the U.S. Fish and Wildlife Service, which estimates the population fell from about 384 million butterflies in 1996 to a record low of roughly 14 million in 2013—a decline of more than 96%.
Each fall, eastern monarchs from across the United States and Canada migrate to a small area of mountain forest in central Mexico, where scientists estimate the population by measuring the acreage occupied by overwintering butterfly colonies. According to the annual 2025-26 survey conducted by World Wildlife Fund-Mexico and its partners, the population rebounded 64% from the previous winter, occupying 7.24 acres of forest. Still, that remains well below the roughly 15 acres of occupied winter habitat scientists consider necessary for a resilient eastern monarch population.
A community project years in the making
ReWild North Fork’s Nancy DePas Reinertsen traces the Custer Preserve project back to early 2023, when she and her husband, Ralph Reinertsen, joined the Southold Peconic Civic Association’s environmental committee after becoming involved with the Suffolk Alliance for Pollinators.
Working alongside civic volunteers, Southold Town officials, ReWild Long Island and Group for the East End, they began looking at a neglected section of Custer Preserve that had become overrun with invasive vegetation, particularly poison ivy.
The original vision in 2023 was modest — roughly 1,200 square feet of native plantings. But the site evolved as volunteers and town officials worked through the realities of the landscape. The town supplied fencing, mulch, cardboard and other materials while volunteers contributed hundreds of hours of labor. Through a ReWild Long Island grant, the project received professionally designed planting plans, native plants and drip irrigation. Volunteers committed to maintaining the garden for at least several years while it matured.
Today, entering its third growing season, the once-weedy patch has become a dense mosaic of native wildflowers, grasses and shrubs humming with bees and butterflies.
“It’s amazing what happens when you remove invasive plants and give native species the opportunity to reclaim a space,” Ralph Reinertsen said. While weeds still require regular maintenance, he said, native plants become increasingly competitive as they establish themselves.
Even as a newly certified Master Gardener, Nancy DePas Reinertsen said she quickly learned that traditional gardening and restoring native ecosystems require very different skill sets. She credits Group for the East End outreach director and educator Taralynn Reynolds with changing the way she now thinks about plants, pollinators and habitat.
More than a butterfly garden
Reynolds said that a Monarch Watch Waystation is a habitat designed to support every stage of a monarch butterfly’s life. That begins with milkweed. Female monarch butterflies lay their eggs exclusively on milkweed. Once the eggs hatch, the caterpillars feed only on milkweed leaves before eventually forming chrysalises and emerging as butterflies.
But Reynolds said milkweed alone isn’t enough. Adult monarchs also require nectar from a variety of flowering plants throughout the growing season. That’s why the Custer Preserve garden includes species like Joe-Pye weed, goldenrod and other native flowers that bloom at different times.
“You have to provide additional nectar sources,” Reynolds said. “The milkweed is going to provide food for the caterpillars, but then they’re going to move around looking for those other nectar sources.”
A journey
Reynolds said that you don’t need a large property to create a native garden.
“You can have container gardens with milkweeds in them,” she said. “The idea is to just start. Don’t be intimidated. Native plant gardening is a journey.”
She also encourages beginners to let go of the notion that they need to create a perfect garden from the start. Some plants will fail. Others will flourish. Wildlife will eat leaves. Insects will appear. It’s all normal.
Reynolds believes one of the biggest hurdles isn’t horticulture — it’s changing the way people think about their gardens. Traditional landscaping teaches homeowners to view insects as pests and damaged leaves as problems to solve. Native gardening asks people to see those same signs as evidence that an ecosystem is beginning to function again.
“You’re going to have to retrain your brain,” Reynolds said. “The whole point behind this is to start bringing wildlife and pollinators back in. It’s a healing process — inviting nature back and connecting back with nature at home.”
Many people associate milkweed exclusively with monarch butterflies, but Reynolds said it serves as what ecologists call an umbrella species. Milkweed supports monarch caterpillars, but it also attracts numerous other insects that become food for birds, reptiles and amphibians. Insects that chew on the leaves aren’t necessarily harming the garden.
“They belong on milkweed,” Reynolds said. “Those insects are part of the food chain.”
Building a food web
The Group for the East End outreach director said monarch butterflies can serve as an entry point to a broader conversation about restoring native habitat. She said this week marks National Moth Week, and that moths receive far less attention than butterflies despite playing an equally important ecological role. Their caterpillars are a critical food source for birds and many other wildlife species.
“Insects are the base of the food chain for all wildlife.”
More than 90% of terrestrial bird species feed insects to their young, making healthy insect populations essential for birds as well as pollination.
She encourages residents to preserve native trees whenever possible, reduce unnecessary pesticide use, limit outdoor lighting that disrupts nocturnal insects and choose native plants that evolved alongside Long Island’s wildlife.
One particularly important recommendation concerns milkweed itself. While tropical milkweed is commonly sold in garden centers, Reynolds advises homeowners to avoid it. Instead, she recommends planting milkweed species native to Long Island, including common milkweed, swamp milkweed and butterfly weed.
“We want to be planting native-to-your-region milkweeds,” she said.
Learning by doing
Sofia Vallecillo, an environmental educator with Group for the East End, said working alongside Reynolds inspired her to plant a native pollinator garden at her mother’s home in Ronkonkoma. It’s small, she acknowledged, but it’s a start.
“It doesn’t look like much,” she said with a laugh. “There’s like three plants here.”
But that is precisely the point. She deliberately chose plants native to Long Island, after considerable research to find species that were both ecologically appropriate and appealing to her mom. Over time, she expects those plants to establish deeper root systems, self-seed and gradually expand with less maintenance.
For new gardeners, she recommends watering newly installed plants deeply around their root zones until they’re established, while paying attention to what the plants themselves reveal through wilting or other signs of stress. She hasn’t yet attracted monarch butterflies, but bees have already found the garden, and that’s a success.
A good starter native garden plant is the Patridge pea, Reynolds said.
“It’s one of my favorite plants. It is so cute. It’s a legume, so it actually fixes nitrogen. It captures atmospheric nitrogen and turns it into usable nitrogen in the soil for itself and other plants around it. Plants in the pea family usually do that. It’s a bee attractant. Other insects will go to it and nectar from it.”
Native plant and garden resources
For more information on native gardening, the nonprofit Xerces.org offers a native plant seed and services directory, as does Doug Tallamy’s HomegrownNationalPark.org website. MonarchWatch.org includes a deep well of resources on monarchs, from creating your own monarch waystation to “butterfly gardening” guides and migration maps. The website for the Long Island Invasive Species Management Area, an islandwide coalition of organizations, provides extensive charts and tables with images of invasive and native species and briefings on how to identify and manage the invasive ones.
