Nancy Clarke, an unflappable artisan who as White House chief florist navigated the tastes of the six presidents and first families she served, died Jan. 14 at a hospital in Richmond. She was 66.

She had complications from a respiratory ailment, said her husband Michael Clarke.

Mrs. Clarke retired in 2009 after more than three decades at the White House and moved to Richmond from Vienna last month. A former flight attendant, she began studying floral design when she was in her 30s and joined the president’s floral staff as a volunteer during the Carter administration.

Fresh flowers, the most ephemeral element of home decor, play a vital role in the aura that presidents and their families create during their time in the White House.

Jacqueline Kennedy favored extravagant bouquets designed in the European tradition. Since the Obamas arrived, the White House has been bedecked in edgy arrangements with surprising touches, such as hot peppers and Brussels sprouts.

In 1985, Mrs. Clarke replaced retiring chief florist Dottie Temple. Mrs. Clarke’s talent, Temple said yesterday in an interview, was her “wonderful sense of color” and “innate sense of proportion and style.”

“Pleasing the first lady,” Mrs. Clarke wrote in a recently released memoir, “was more important to me than anything else.” She learned that Nancy Reagan loved peonies above all other flowers, Barbara Bush liked lavender, Hillary Rodham Clinton admired tropical varieties, and Laura Bush enjoyed more traditional ones. Michelle Obama is partial to forsythia.

A stickler for decorum, Mrs. Clarke arrived at the White House most mornings around 6 — just in time for flower deliveries — and often did her clipping and trimming in a dress suit. Like most White House florists, she worked closely with first ladies on projects including state dinners and Oval Office arrangements.

In 1985, when the Reagans hosted Prince Charles of England, Mrs. Clarke filled vases with hundreds of roses. They can be seen in the background of the memorable photos of John Travolta dancing with Lady Diana, her dark gown swirling around her.

At Christmastime, Mrs. Clarke was involved not only with designing White House floral arrangements, but also with seasonal decorations throughout the property.

Nancy Kay Frisby was born May 14, 1945, in Mundelein, Ill. In the 1970s, she began working at a floral shop in Dayton, Ohio, where her husband had been stationed by the Air Force. She enjoyed the work so much that in 1977 she decided to enroll in the now-defunct Hixson’s School of Floral Design in the Cleveland suburb of Lakewood.

Soon afterward, she and her husband moved to the Washington area. On the suggestion of her instructor at the floral school, she called the White House and offered her services as a volunteer.

Survivors include her husband of 44 years, retired Air Force Col. Michael Clarke of Richmond; two children, Christopher Clarke of Pacifica, Calif., and Suzanne Newton of Richmond; two sisters; and two grandchildren.

Although Mrs. Clarke often catered to the tastes of the first ladies, she did not overlook their husbands. She kept track of President Bill Clinton’s allergies and President George W. Bush’s color preferences.

“For the longest time, we used to keep a bowl of peach-colored roses on Bush Two’s coffee table in the Oval Office,” Mrs. Clarke once told The Washington Post, referring to President George W. Bush. “We changed them to red and that lasted five minutes. We got a call that the president wants the peach roses back.”

She once designed a floral arrangement for Bush’s birthday party. In tribute to his former role as a co-owner of a Texas baseball team, she crafted a baseball made from carnations.