The Seed Collector

Heather Liljengren hunts for seeds in the open spaces near New York City. The seeds she collects could mean the survival of native plant species and habitats, both in the five boroughs and beyond.

The Seed Collector from Scienceline on Vimeo.

Preserving native plants in and around New York City
By Douglas Main

The sun had just begun to rise over the deserted coast of Brooklyn’s Marine Park. Heather Liljengren was early. She put on her boots and ventured into the shallow water. Great blue heron and white egrets silently stalked prey amidst thickets of saltmarsh bulrush. Waterbirds flew here and there, intent on a morning meal of minnow or prawn. Taking in all the beauty, she couldn’t help but think to herself, “I’m in Brooklyn?” But it was a fleeting thought, and there was an important population of salt marsh grasses whose seed she needed to collect.

Liljengren helps to preserve the vital, often overlooked green spaces tucked into America’s biggest city. As a taxonomist and seed collector at Greenbelt Native Plant Center in Staten Island, it’s her job to collect seeds from many of the 1,000 or so native plants within a 100-mile radius of New York City. These seeds are then used to restore critical habitats in disturbed ecosystems throughout the five boroughs and beyond.

Some of the seeds are also sent to a national center in Fort Collins, Colorado, in an effort to preserve all of the U.S.’s flora. Placed safely in long term storage, the seeds can remain viable for hundreds of years. “If an apocalypse happens maybe some of my seeds will get out there,” she says, half-joking.

Liljengren mostly focuses on native “workhorse species,” or those that produce bountiful seed from which damaged ecosystems can be restored. After collecting them in the field and carefully noting their location, she brings her small treasures back to the lab, cleans and sorts them. Finally, she painstakingly catalogues the seeds in the center’s bank, a large walk-in cooler kept at 60 degrees Fahrenheit and 15 percent humidity, which keeps them viable for 10 years or more.

Liljengren says she “grew up in the woods.” During her childhood in Connecticut, she often accompanied her dad hunting. Her mother tended a vegetable garden, and she grew up loving plants. After going to the University of Massachusetts at Amherst, she landed an internship at the National Tropical Botanical Garden in Hawaii. There, amongst other projects, she helped restore a beach habitat that had been abandoned by egg-laying sea turtles due to a proliferation of invasive Zoysia grass. She helped re-plant it with several native species the turtles prefer. But she was soon drawn back to the East coast to her friends and family. “The people in Hawaii say that if you are meant to be there, the islands will call you back,” Liljengren says. But she wasn’t meant to stay at the time.

An internship at Brooklyn Botanical Gardens followed her Hawaiian stint, where she collected seeds from the expansive gardens before planting and raising them. She met her current boss Camille Joseph during a field trip to New Jersey’s Pine Barrens and arranged to go seed collecting together in the Garden State’s Great Swamp National Wildlife Refuge. Liljengren was thrilled to collect seeds from wild plants, and realized then and there that’s what she wanted to do. So when Joseph offered her a job, she accepted.

Last October a reporter accompanied Liljengren as she tromped through Staten Island’s Victory Park looking for jump seed, or Polygonum virginianum, a native three-foot tall plant whose elegant green flower spikes are rich with white blooms that gradually whither into brown seeds. You have to swipe them off quickly, though, or else they will spring or jump away from the plant (hence the name).

“Collecting is all about stripping and pulling and plucking,” she says, “getting the seed any way you can.”

From March to November, Liljengren travels throughout the 25 counties in and around New York City to collect seeds. Having evolved within the area over hundreds or thousands of years, native plants “support the working ecosystem that they are a part of,” Liljengren says. “They are ‘the right plants in the right place.'”

But sometimes there are not enough seeds to fill her bags.

“Everybody wants butterfly milkweed because it’s orange and pretty and attracts butterflies,” she says. “But there are very few places where it doesn’t get mowed down before the seed can set and I can get there in time.”

After a disruptive event such as a fire or bulldozing for construction, native habitat is often decimated. Species such as butterfly milkweed are some of the first hearty plants to arrive on the scene, colonizing the newly bare earth. The ecological march of species goes on, though, and the milkweed lays the foundation for larger species, such as trees and shrubs, which out-compete and displace it. Though a pioneer, the milkweed doesn’t last long. Liljengren feels it is her responsibility to help maintain the genetic diversity of milkweed and other native plants before it’s too late.

“There is the constant pressure of: I’ve got to get out there, I’ve got to get out there, I’ve got to get seed,” she says. “I have nightmares about it, about acorns that I didn’t get because the deer ate them or I couldn’t find them.”

Co-worker Lauren Stewart describes herself and Liljengren as “two of the more neurotic people on the job.” For example, on Liljengren’s birthday she advised Stewart on how to perform a final sift of seeds from a sample of purple love grass, from which Stewart garnered about one million extra seeds. “Granted they are very small, but they’re still viable,” Stewart says.

Afterward Liljengren crushed up leaves of Woodwardia areolata, or Virginia chain-link fern, to release their spores.

“In the end it all falls on me,” Liljengren says, “because if there are no seeds, there are no plants.”