Rated R. At the Coolidge Corner.

Writer-director Paul Schrader is best known as the writer of the landmark Martin Scorsese masterpiece “Taxi Driver” (1976) – the film that immortalized the line, “You talkin’ to me?” – and the writer-director of such films as “American Gigolo” (1980), “Cat People” (1982), “Affliction” (1997) and more recently “First Reformed” (2017). At 76, Schrader now delivers “Master Gardener,” a “First Reformed”-like third film in a trilogy including “First Reformed” (2017) and “The Card Counter” (2021), all featuring deeply troubled protagonists. In this case, the lead is a horticulturist devoted to maintaining the lavish gardens and grounds of the estate of a demanding dowager (Sigourney Weaver), who calls him, “sweet pea.”

The metaphor is arguably too on-the-nose. In addition to summoning the memory of Voltaire’s “Candide” and its garden, the profession of Schrader’s latest alter ego reminds us that all of Western civilization began in a garden named Eden from which our spiritual parents were expelled.

The oddly-named Narvel Roth (Australian actor Joel Edgerton) – odd for a former neo-Nazi – has a secret. Some time before he became a master gardener, Narvel was a bearded member of a right-wing militia of some sort. Presently, however, he writes in a journal about the three types of gardens. His employer Norma Haverhill, owner of Gracewood Gardens, informs Narvel that she wants him to hire her young and beautiful grandniece Maya (Quintessa Swindell) – another of Schrader’s name-game names.

Maya has fallen in with a bad crowd down the road of Schrader’s mini-universe. It’s Narvel’s job to, excuse the pun, cultivate Maya. She’s a garden, too. Will Narvel have to pull out some weeds in the process? I have no doubt. I love the smell of loam in the morning.

Seeds can endure for over a thousand years, we are told. As it turns out, Narvel has some souvenirs of his dark past in the form of neo-Nazi tatts, including several swastikas, on his torso. Edgerton is intense as Schrader’s latest striver. For reasons not entirely clear to me at least, Norma’s living room is covered – ick – in jellyfish wallpaper. Norma has a big charity auction event coming up. She wants the grounds to look perfect. She also wants Narvel to take her to bed and show her his tatts. Yes, kinky things grow in this garden, too.

Is Narvel redeemed by his profession? “Laborare est orare” (Latin for, “work is prayer”) is true for many of us, Narvel included. A person from out of Narvel’s past named – ahem – Detective Neruda (Esai Morales) reappears, complicating matters even further. Will another Schrader character have to violently drag another young woman out of the clutches of hell? Will there be blood? For Schrader that hell might be a metaphor for his strict Calvinist upbringing, which has given him a stark, lifelong, Bressonian view of the world. It’s “Pilgrim’s Progress” all-the-time and one, original sin and sinner after another. Like Travis Bickle of “Taxi Driver,” Narvel feels compelled to save someone from the devil. Like so many of Schrader’s heroes, he simply can’t help himself.

(“Master Gardener” contains profanity, nudity and sexually suggestive content)