The filming of the antidrug message that Nancy Reagan and Hollywood tough guy Clint Eastwood are delivering in motion picture theaters around the country was hardly a secret. The White House announced in May that Mrs. Reagan would join Eastwood to do the public service announcement for a series of star-studded trailers produced by the motion picture industry.

But when Attorney General Edwin Meese III read about last week's White House premiere of the trailers, the film world's project came as news to him. As head of the National Drug Policy Board, Meese is supposed to be kept informed of all government efforts -- including Mrs. Reagan's for the White House -- to reduce both the supply of and the demand for illegal drugs.

"I don't think he's upset," said one government source, "but it took him very much by surprise and he's been trying to find out why no one told him."

"He did not take the slightest offense at not having been invited," said Justice Department spokesman Pat Korten of the premiere. "He was going out of town and could not have attended anyway. He's not one of those social butterflies who has to go to all those gala things."

Meese and others on the Drug Policy Board will see the trailers Thursday at their regular meeting, Korten said.

And tomorrow at the White House, Meese, who is still smarting over recent congressional criticism that he heads a disorganized drug program riddled by internal dissension, will be very much in evidence.

Together with Mrs. Reagan, Education Secretary William J. Bennett and actress Drew Barrymore, Meese will help launch a campaign urging 10 million school kids to sign "Just Say No" to drugs pledge cards before the start of school. Meese will speak on the "Federal Role in the National Crusade for a Drug Free America."

Campaign cosponsors are Proctor & Gamble and the Just Say No Foundation, with support from private business.

Moscow's Bolshoi Ballet, opening tonight at the Kennedy Center as part of its first American tour since 1979, toured the White House yesterday, and there to welcome the dancers was the First Twinkle Toes herself.

"I had hoped you weren't expecting me to do a tour jete', since I don't have the right shoes," apologized Nancy Reagan, who has done just about every other dance at one public function or another since her husband became president.

As might be expected of world-acclaimed dancers, the Soviets were on their toes for just such an excuse. Stepping forward to present a pair of multiautographed, pale pink satin toe shoes to Mrs. Reagan was Soviet Ambassador Yuri Dubinin.

"Just your size," said Dubinin in English, which when translated delighted the Soviet visitors.

According to the White House, Mrs. Reagan's shoe size is 7 1/2. She did not, however, try on the shoes to see if they fit.

The Rose Fitzgerald Kennedy Garden was dedicated in Boston yesterday in tribute to the mother of an American president and two U.S. senators as well as to other Gold Star mothers -- women whose sons or daughters died fighting for this country.

Mrs. Kennedy's first son, Joseph P. Kennedy Jr., died Aug. 12, 1944, on a combat mission over the English Channel; two other sons, President John F. Kennedy and Sen. Robert F. Kennedy, were assassinated. Mrs. Kennedy wasn't at the dedication ceremony, but her youngest son, Sen. Edward M. Kennedy, represented her.

"Mother liked the Rose Garden in the White House, but even more than that, she loves the rose garden here, which will be hers forever, and where the flowers will take their roots beside her own," Kennedy said of the $700,000 project.

Situated in the north end of Boston where Mrs. Kennedy grew up and where her father began his political career, the one-acre park features a rose garden whose several varieties include the John F. Kennedy rose.

Mrs. Kennedy, whose 97th birthday is tomorrow and who is one of eight Kennedys who celebrate July birthdays (including Jacqueline Kennedy Onassis who will be 58 on July 28), had ice cream and cake at her home in Hyannis Port with several members of the family who visited her over the weekend.

What may have clinched Sen. Alan Cranston's support was the senior King Clone, an 11,000-year-old creosote bush said to be Earth's oldest living organism.

A ring of evergreen about 65 feet in diameter and 329 feet in circumference, it grows in California's Johnson Valley desert within a few hundred feet of a favorite track frequented by motorcycle, off-road vehicle and all-terrain vehicle drivers.

Cranston, who is testifying at today's hearings on the California Desert Protection Act, claims that in tearing across the terrain, these thrill drivers have already destroyed other King Clones, younger but still thousands of years old.

"It's such a fragile environment, not only animals and plant life are at risk but so is the desert, which doesn't heal well. The tracks of World War II Army vehicles on maneuvers there more than 40 years ago are still imbedded and visible," Murray Flander, a Cranston spokesman, said yesterday.

The proposed legislation grew out of environmentalists' determination to create three national parks and 85 wilderness areas out of 7.5 million acres in southeast California, thereby removing them from the Bureau of Land Management and placing them under the more rigid control of the National Park Service.

Testifying at Thursday's hearings will be actresses Shelley Duvall and Morgan Fairchild, an amateur paleontologist, and Robert C. Stebbins, preeminent U.S. authority on reptiles. All three will be at a reception tomorrow night hosted by environmental lobbyist Scootch Pankonin at her Constitution Avenue NE home.