(FORTUNE Magazine) – Not many people can say with certainty that they've repeatedly met the demands of Larry Ellison, one of the world's wealthiest and most famously difficult-to-please businessmen. Then again, Ellison has never asked any of his charges at software maker Oracle to design and build a Japanese stroll garden for him. He has turned, however, on four separate occasions to landscape architect and fellow Japanophile Ron Herman, who has parlayed his relationship with Ellison into becoming something of a gardener to the plutocracy. He is certainly one of a select few gardeners who have their own publicist. Herman's next project for Ellison, which is about to be unveiled, is his most magnificent yet. For the past eight years he has been creating the gardens for a $120 million, 25-acre Japanese village in Woodside, Calif., in the rolling hills south of San Francisco. How does Ellison rate as a client? "He's very decisive," says Herman diplomatically. Clearly, cultivating the ultimate Zen garden is a respite from hostile takeovers, demanding yacht races, and the like. Says Herman: "He seems very happy when he's working on his building projects." After all, what price serenity? --Adam Lashinsky