The retired teacher, who moved to Southport, N.C., last year and was building a home along the Cape Fear River with his companion, Ethel Taylor, was 69.
Mr. Heath was born in Massachusetts, the youngest of three boys. His father worked in insurance and his mother ran the household while maintaining a boutique clothing business on the side.
In 1961, Mr. Heath graduated from the private Tabor Academy in Marion, Mass. He went on to earn a degree in French in 1966 from Franklin & Marshall College in Lancaster, Pa., where he also played football and lacrosse.
After college, Mr. Heath came to Maryland and taught French at St. Paul's School in Lutherville-Timonium and the Tome School in Cecil County, family members said. He left in the late 1960s to live and travel throughout France, while earning a master's degree in the language from the Paris-Sorbonne University.
In France, he met his first wife, bringing her back with him to the United States, where he took a job teaching at the Friends School in Baltimore in the 1970s. The couple lived in northern Baltimore and had a son in 1977. The marriage ended in divorce.
Mr. Heath left Friends to teach at the McDonogh School in Owings Mills for a couple of years in the early 1980s, then took a break to earn a degree in Spanish from the Johns Hopkins University.
"There's a bit of crossover between the two languages," and learning to speak Spanish fluently was "a way to open the door on another culture," said his son, Milan A. Heath II of Cockeysville.
Mr. Heath returned to teaching, this time at the Gilman School in Baltimore, and traveled when he could to Europe and Central and South America.
"That was kind of his way to meet new people and learn things about other cultures," Milan Heath said.
Mr. Heath married again and frequently traveled to France with his second wife. In 1983, they had a daughter, Celia, whom he took to Paris for her 13th birthday. Ms. Heath, who lives in Los Angeles, remembers being awed by her father's ability to converse like a Frenchman.
"French people often couldn't believe that he was American," she said. "He was totally curious and totally fascinated by the French culture. I know that was his No. 1 love."
Mr. Heath's marriage to her mother also ended in divorce, but both children say they had strong relationships with their father.
Milan Heath recalled twice-daily walks and personal tutoring in French.
"He felt really strongly about spending time with us every day," he said. "He always taught us [that] family was really important, as well as being honest."
Ms. Heath remembered her father's ability to shut out all distractions when it came to his children.
"It was really important that … anything that was going on in his outside world and my outside world" did not interfere with their relationship, Ms. Heath said. "He taught me a lot about being independent and strong."
Mr. Heath, who also coached lacrosse and soccer teams, retired from teaching in 1993. He opened the Bridge Farm Nursery in Cockeysville, where he quickly earned a reputation as a master grower of peonies and hydrangeas, driven by perfectionism and a strict attention to detail, his family said.
His mother had a passion for landscaping and Mr. Heath picked up some of her best skills, his son said.
In addition to travel, Mr. Heath's hobbies included walking, exercising and playing the acoustic guitar, mostly music from his youth in the 1960s and 1970s. He was also a fan of detective novels and crime stories and donated to his alma maters frequently. He was a "fervent supporter" of Franklin & Marshall, Milan Heath said.
Mr. Heath retired from the nursery business and moved with Ms. Taylor to North Carolina, where he'd traveled for vacation trips over the past decade. He was at home when he died.
Said his daughter: "I do believe that he was the happiest he'd ever been, and that he was with his true love."
In addition to his two children and his companion, Mr. Heath is survived by four grandchildren.
Mr. Heath requested that no funeral services be held, though his family plans to have a private memorial reception in Maryland this summer.