If you're planning to visit New York City, or you live in one of its boroughs and wonder when's the best time to visit the High Line — the dynamic garden stretching a mile and a half through several neighborhoods on an abandoned, historic and elevated rail line — Andi Pettis has an easy answer.

Today. Next week. Or the week after that. Or the week …

"There is really no bad time to visit," said Pettis about the public park on Manhattan's West side. Pettis should know. As the High Line's director of horticulture, she understands that Piet Oudolf, one of the world's most innovative garden designers and the designer of the plantings on the High Line, created the plantings to be enjoyed in every season. "It is always interesting and beautiful," said Pettis. "It's learning to look at the plants and the composition in a new way. It's just a new way of looking at gardening."

Besides a new way of looking at things, gardeners might find several other aspects of the High Line (which was once scheduled for demolition) remarkable. One, it's helping to create a living corridor though Manhattan. Another is that caring for the plants on the High Line is similar to taking care of a home landscape, no matter where in America you might live.

The High Line's impact on visitors

Plants grow in the High Line, near a bench. The High Line offers a plant-filled respite from Manhattan's concrete jungle.

Before the High Line began opening in sections in 2009 (the last section is scheduled to open in 2018), the rail bed, while sitting on supports that were structurally sound, had fallen into a state of disrepair. In effect, it was a completely wild garden of grasses, flowers and sumac trees that winds and birds had sown naturally among billboards and industrial relics. To New Yorkers, it was a true wilderness in the middle of their densely populated city, and they loved it.

Friends of the High Line, which maintains, operates, and creates programs for the High Line in partnership with the New York City Department of Parks & Recreation, found out just how much New Yorkers loved the naturalized High Line when they held a series of community input sessions to hear what the public thought about developing the High Line into a cultivated garden. They got an earful. High Line co-founder Robert Hammond remembers one response so well he wrote about it in the introduction to "Gardens of the High Line: Elevating the Nature of Modern Landscapes," a lavishly illustrated book about the High Line by Oudolf and photographer Rick Darke. "The High Line should be preserved, untouched, as a wilderness area. No doubt you will ruin it. So it goes."

Oudulf, of course, didn’t ruin it. The primary reason for that, Pettis believes, is Oudolf's approach to garden design. "Piet's style is so naturalistic, his work kind of emulates nature," said Pettis. She remembers that when the High Line first opened that one of the questions Friends of the High Line would get was whether or not the plants were ones that grew there before the High Line, on their own. "People were surprised when we told them no and explained that this was actually designed this way.”

That led to other questions about the landscape, which Pettis characterized as heavy with grasses and wildflowers and looking like what people see from car windows when driving down the freeway. "We would have people ask, 'Where are the plants? Where are the flowers? Why is it all weeds?'

Plants and grass growing on the High Line The High Line is filled with grasses and wildflowers that give off a meadow feeling in the middle of the city.

"We don't get those kinds of questions nearly as much anymore," Pettis says. "Now, people have become familiar with this style of garden, and they are thinking about the four-season garden." While some people still just see "dead plants" in January, many others have the "interest and the capacity to stand back and look at the big picture and really see the beauty in it. That’s been gratifying and really exciting," said Pettis.

Something else she finds gratifying are visitors — some 7.7 million people visited the High Line in 2016 — who understand that Oudolf uses the entire life cycle of a plant in his designs. "It's not just about the pretty flower, it's also about the texture of the leaves, how the light plays off them, the color they have in the fall, how they bleach out in winter and how the seed heads provide structure in the garden through the winter. I think all of those are something that has expanded people's idea of how you can use plants in a landscape and in a garden."

Another way that the High Line is helping to change perceptions of gardening, Pettis said, is the impact the High Line has had on the use of native U.S. plants. "The High Line opened at a time when using native plants in gardens and landscapes was really just beginning. It was very, very innovative at the time," Pettis said. "Now you can go to the box stores and they are carrying selections of native plants. So, I think the High Line also contributed to the native plant movement."

A High Line gardener inspects a plant along the Interim Walkway. A High Line gardener inspects a plant along the Interim Walkway. The plants in this area are all wild and not part of the 'designed' garden.

Oddly enough, this has led to one of the misconceptions about the High Line. Pettis estimates that only about 50 percent of the plants in the elevated garden are U.S. natives. "The planting is so naturalistic and creates such a palpable sense of place that people think all of the plants are natives. Piet's designs are cosmopolitan. He is inspired by a lot of Midwestern landscapes, so he uses a lot of native plants from both the Midwest and the Northeast. But he also uses a lot of garden varieties from Asia and Europe. In particular, he uses European plants that he is familiar with from breeding his own plants and having his own nursery. His artistry incorporates introduced species into landscapes in a way that makes them look like they fit, so people tend to think our plantings are all native when they are not."

People also think the plants growing on the High Line now are the same plants that grew there before the restoration began. That’s true in only one section, the Interim Walkway around the rail yards, which is temporarily being left as nature created it so that visitors can see the wild landscape juxtaposed with the designed landscape. Most plants are sourced from contract growers within 500 miles to support local growers and hold down carbon emissions in transporting plants to the High Line.

Even in the cultivated areas, though, nature is still having her way with human intervention through natural plant distribution. Some plants have moved from the wild area into the managed portion. These include an aster (Symphyotrichum ericoides), a tragopogon (Tragopogon dubius) and a little viola (Viola macloskeyi var. pallens). "We are cultivating the viola because we found that it is working as a really great ground cover," Pettis said.

A habitat corridor in Manhattan

A butterfly lands on a plant in the High Line The High Line attracts pollinators like butterflies.

The High Line has caught the attention of urban planners worldwide and inspired some to re-think how they can re-use infrastructure for public space and greenspace, Pettis said. "Friends of the High Line is cultivating a network of those kinds of projects all over the world to give us a platform to talk with each other. We also talk about what's working and what’s not and how we can do things better going forward and how new projects can learn from the successes and challenges of all of us. That is something we’ve been working on the past year and a half or so."

The group is also beginning to document migratory birds and pollinators that are being observed on the High Line as well as plants showing up in the cultivated areas that were not planted there. The documentation is being done in collaboration with researchers at Columbia University and with the Sustainable Sites Initiative of the Landscape Architecture Foundation.

"I think that more importantly than the High Line being a habitat on its own, it is becoming an ecosystem in network with all of the other greenspaces popping up in this part of Manhattan," said Pettis. "There’s a green roof on the Javits Center and the Hudson River Park is all up and down the West Side adjacent to the High Line. I think in network with all those other green spaces, we really are creating a habitat corridor and an ecological corridor that are functional and are really making an impact. That is exciting."

Just like gardening at home

Plants grown between old railroad tracks The High Line takes advantage of its surroundings to give it a unique look.

Perhaps the most surprising thing about the High Line is that other than gardening in relatively shallow beds — the average planting depth, even for large trees such as bur oaks, is often only 18 inches, Pettis said — gardening on the elevated rail line in the shadow of Manhattan's skyscrapers is much like gardening in a suburban lot.

  • A pleasing design is as much a high priority in individual as public gardens.
  • Home gardens typically include native plants as well as introductions from other countries (though, hopefully not invasive plants and hopefully the mix approaches the 50-50 that the High Line has).
  • As in many home gardens, some plants on the High Line are chosen to attract pollinators.
  • Some plants on the High Line don't survive and are replaced with different selections. Home gardeners can relate.
  • Hitchhiking plants arrive no matter where you garden. Some are pleasant surprises and worth keeping. Others, not so much.
  • Composting is big. Homeowners typically clean up plant debris, especially in the fall. The environmentally conscious add that to compost bins, later adding the compost to the soil to improve soil structure.
  • The garden, whether at home or the High Line, takes on a different kind of beauty in winter that allows the structure of trees and some other plants to be appreciated in a way that is not possible when their branches and stems are filled with foliage.

Other than its location, one aspect of the High Line distinguishes it from a home garden. In its short eight years, the High Line has become one of the world's most popular destinations for Instagram shots. That's a distinction many homeowners are glad to see go to New York City.

For more information

Here's a link to the High Line’s latest bloom list. Previous months' versions are available in the drop-down menu.

Friends of the High Line is responsible for raising all operating funds for the park. They do that through a variety of revenue streams, including individual and corporate donors and government and foundation grants. The New York Economic Development Corporation breaks down initial funding streams here.

Photos by Rick Darke and taken from "Gardens of the High Line: Elevating the Nature of Modern Landscapes" © Copyright 2017 by Piet Oudolf and Rick Darke. All rights reserved. Published by Timber Press, Portland, Oregon. Used by permission of the publisher.