“W.S. Merwin: To Plant a Tree”

Airs 8 p.m. Saturday on PBS

A one-hour documentary, “W.S. Merwin: To Plant a Tree,” featuring the prize-winning poet and his wife, Paula, and their garden in Haiku, Maui, has been airing across the nation in celebration of Earth Day and April as National Poetry Month.

Merwin, a National Book Award winner who has twice won the Pulitzer Prize and been U.S. poet laureate, first came to Maui in 1976 to study Zen Buddhism and decided to settle there, buying 19 acres of what had been a pineapple plantation. As Merwin recounts in his new collection of prose and poetry, “What is a Garden?” it was a barren space, a “paradise lost.”

The couple began planting what would grow, including what turned into one of the most extensive private collections of palm trees from around the world. They also cultivate native plant species and have started a nonprofit foundation, the Merwin Conservancy, to support the garden as a center for environmental advocacy and, eventually, a retreat for writers and botanists.

“One of the conservancy’s goals, and the dream and vision of Mr. Merwin, is to protect this sanctuary at the intersection of art, spirituality and nature,” said Jason Denhart, executive director of the Merwin Conservancy. He noted the poet’s house is “completely off the grid,” with photovoltaic and water catchment systems.

“W.S. Merwin: To Plant a Tree” is a production of Cicala Filmworks in association with Thirteen Productions LLC for WNET. It originally premiered on PBS Hawaii in 2015 in a version that was a half-hour longer. The current broadcast of the edited version by more than 100 PBS affiliates nationwide is being sponsored by the Halekulani, which this month announced a partnership with the Merwin Conservancy to help support its mission.

For more information, go to merwinconservancy.org.