Rachel ‘Bunny’ Lambert Mellon [1910-2014]; Heiress famed for designing Rose Garden

Rachel (Bunny) Lambert Mellon, an avid gardener, in gardening attire in 1982.

Rachel “Bunny” Mellon, the very elegant, very private widow of philanthropist, art collector, and Pittsburgh native Paul Mellon, died at her home Monday in Upperville, Va. She was 103.

A close friend of First Lady Jacqueline Kennedy and later, more controversially, a strong supporter of 2008 Democratic presidential candidate John Edwards, Mrs. Mellon was married for more than a half-century to the heir to one of Pittsburgh’s greatest fortunes. She became known in her own right as the designer of the White House Rose Garden, as well as an expert on landscape design, architecture, and the history of gardens. Her collection of rare garden books, manuscripts, and botanical prints was the envy of horticultural scholars.

Mrs. Mellon’s close friendships ranged from actor Frank Langella to Mrs. Kennedy, who was introduced to her in the mid-1950s by Adele Douglas, Fred Astaire’s sister, who lived next door to Mrs. Mellon in Fauquier County, Virginia.

Mrs. Mellon proved indispensable when Mrs. Kennedy took on the task of restoring the White House, and in later years, she designed the gardens at the Kennedy Library in Boston.

An heir to the Listerine fortune, Mrs. Mellon was born to great wealth and married more of it, but never lost herself in it. She grew up in Princeton, N.J., attending Miss Fine’s School and Foxcroft, and then married Stacy B. Lloyd, Jr., a Princeton graduate who roomed with Paul Mellon in London during World War II when both were assigned to the Office of Strategic Services, the forerunner of the CIA.

After the war, in 1946, Paul Mellon’s first wife, Mary, died after a severe asthma attack. He married Bunny Mellon in 1948 after her divorce from Mr. Lloyd. Both had two children from their first marriages. Mr. Mellon died in 1999, at 91.

Her grandson described a “fiercely loyal, wonderfully kind” woman devoted to family, friends, and more than 100 employees who staffed her seven homes.

Ms. Bedell Smith, author of Grace and Power, a book about the Kennedys’ White House years, recalled being told by the duchess of Devonshire that Mrs. Mellon “lived in her own realm of beauty and perfection.”

“Nothing should be noticed. Nothing should be noticed,” she told New York Times reporter Sarah Booth Conroy in 1969, saying it twice for emphasis.

That penchant for discretion made it all the more jarring when, at 101, Mrs. Mellon’s name surfaced in a controversial legal battle involving Mr. Edwards, the former U.S. senator, who was charged with using nearly $1 million in illegal campaign contributions — $700,000 from Mrs. Mellon — to resettle his mistress in California.

The media dubbed Mrs. Mellon, who was not accused of any wrongdoing, “Sugar Mama,” but she emerged unscathed. Mr. Edwards was acquitted of one charge, and a judge declared a mistrial on the remaining charges. The Justice Department opted not to retry the case.

In 2010, her name surfaced again in the media, as one of a group that was bilked in a $59 million Ponzi scheme by Wall Street investment adviser Kenneth Ira Starr.

Her passing marks a sea change in upper-class culture, said David Patrick Columbia, founder of NewYorkSocialDiary.com, a blog that chronicles the lives of the rich and social.

“She was all about taste. Faultless good taste. That’s what made her, essentially, an artist. She only became famous because of her friendship with Jacqueline Kennedy Onassis,” said Mr. Columbia.