A 19-acre palm forest in Peahi, painstakingly planted by the acclaimed American poet W.S. Merwin over nearly 40 years, will be permanently preserved, thanks to a conservation agreement with the Hawaiian Islands Land Trust.

A catalog of the property completed this spring determined there are 2,741 individual specimens on the property, representing some 486 taxonomic species, making it the third-largest palm collection in the world, according to Jason Denhart, executive director of the Merwin Conservancy. Experts at the National Tropical Botanical Gardens called it “a living treasure house of palm DNA.”

In an interview, Merwin said the preservation agreement was “a great joy” to him and his wife, Paula.

“It’s a great consolation to us – insofar as anything is permanent, it means you can’t come in with bulldozers someday and turn it into a development,” he said.

A deed of conservation easement permanently protecting the land was signed Oct. 10 by HILT and the Merwin family, according to an announcement.

When Merwin first saw the property almost 40 years ago, it was infertile hardpan. The abandoned pineapple fields covered in scrub brush were classified by the county as “wasteland.”

“It was totally ruined land,” he recalled.

Merwin first hoped to restore a native Hawaiian forest on the property, but he found that the soil was too poor for native plants to grow. He planted some 300 koa trees, but “one by one, they all died.”

After trying a number of Hawaiian plants without success, Merwin found that native palms were the one species that was able to survive and thrive on the land. So, he turned his attention to palm trees.

“I felt, ‘Palms are endangered all over the world, so I’ll see what palms from all around the world will grow here, because they need a habitat,'” he recalled.

One by one, he began gathering seeds and starts, planting them and tending their growth – often watering them by hand.

In addition to planting as many native Hawaiian palm varieties as he could find, Merwin added some rare specimens to his collection. He received seeds for one variety of palm that had been officially classified as extinct – and managed to get it to grow.

He’s gone on to provide seeds collected from the mature tree to a nursery on the Big Island.

Another unusual palm from Madagascar produces shoots that drop off to become new plants.

While Merwin may have come to palms through happenstance, he’s grown to be fascinated by them. While they’re familiar plants, palms remain a scientific mystery, he noted. Little is known, for example, about why coconuts evolved the way they did.

“I think they’re very beautiful, and they’re remarkably adaptable, but they’re really very old,” he said, adding that palms have evolved for some 90 million years.

He said he doesn’t have a favorite tree: “Whichever palm I’m closest to is my favorite at the moment.”

Merwin continued to cultivate his palms as the years went on, eventually losing count of how many he’d planted, even as a lush forest grew up around him.

Finally the Merwin Conservancy arranged for renowned palm expert John Dransfield of the Royal Botanical Gardens Kew to identify, tag, catalog and map each specimen in the collection. The survey, completed this year, determined there were more than 2,700 individual palm trees, making it the third-largest collection in the world.

“(Dransfield) said, ‘This has to be saved,’ ” Merwin recalled.

Information collected in the project, which was completed in partnership with the National Tropical Botanical Gardens, was gathered in a database that will eventually be made available, along with the palm collection, to the academic and botanical community for scientific study.

Denhart said the catalog and preservation agreement fulfill a longtime goal of the Merwin Conservancy.

“Now we know exactly what is being protected – and we’re protecting it,” he said.

While the property in Peahi Valley is not open to the public and is still used as the Merwins’ private home, a long-term plan includes possibly converting the property into an artist’s or writer’s retreat as part of a residency program with Merwin’s nonprofit publisher, Copper Canyon Press.

The Merwin Conservancy is launching a fundraising campaign to support the future maintenance and preservation of the property. For information, visit merwinconservancy.org/giving.

* Ilima Loomis is a Maui-based writer and editor. Do you have an interesting neighbor? Tell us about them at neighbors.maui@gmail.com. Neighbors and “The State of Aloha,” written by Ben Lowenthal, alternate Fridays.