Interior designers and garden clubs deck the elegant halls of the Vanderbilt Mansion in Centerport each year, and hundreds of visitors see the results beginning the day after Thanksgiving. The decorators create enchanted rooms with lighted trees, boughs, ornaments, wreaths, ribbons and elegantly wrapped faux gifts.

Lance Reinheimer, executive director of the museum, said, “These generous volunteers use their time and talent to create an atmosphere of charming holiday grandeur and sophisticated living. We’re grateful to them for bringing magic to this historic house.”

Stephanie Gress, the museum’s director of curatorial affairs, said “Most of these garden clubs and designers have been decorating the mansion for more than 20 years. We look forward to seeing them each year, and to how they use their creative skills to bring elegant holiday charm to the house.”

JoAnn Canino chairs the Three Village Garden Club (Old Field, Setauket and Stony Brook), which has decorated a mansion room every year for more than a decade. “The Portuguese Sitting Room is very masculine,” she said. “We wanted to bring out the colors of the rug and of the sculpture of the knight on the horse — teal, turquoise, pinks, blues and greens.” In addition to decorating the tree, club members added boughs, ribbons and ornaments to the centuries-old mantelpiece.

The Dix Hills Garden Club decorated the striking paneled library, the grandest room in the 24-room Spanish Revival mansion. “It’s a dark room, with not much natural light coming in,” said Christine Lagana. “So we added a wide deep-red ribbon that winds down from the top of the tree. The ‘pop’ of the red brightens the tree in that dark space.” The club used many gold ornaments and enhanced the mantel of the imposing fireplace with green boughs and gold ornaments. “Since this is a museum, we can’t use glue or nails on the carved wood,” Lagana said. “So we wrapped hidden bricks in dark-green felt and used them to secure the boughs, which are intertwined with golden ribbons. Then we were able to hang ornaments securely from the large length of bough that runs along the mantelpiece.”

Claudia Dowling of Claudia Dowling Interiors in Huntington said, “We’re blessed to help decorate the Vanderbilt Mansion. It’s such a beautiful historic, Long Island treasure. In one of the guest rooms, we used gold and cream and a very traditional tree, in keeping with the original concept of how the Vanderbilt rooms were designed and decorated. We added subtle ‘whisper’ touches in one of the guest rooms — a garland on the mantelpiece and surprise gifts on the club chair.”

Jenny Holmes, vice president of the Nathan Hale Garden Club, and her friends decorated the upstairs Organ Room, a paneled parlor with an Aeolian pipe organ, large fireplace and sofa, and a table for playing cards and board games. “Because Mr. Vanderbilt loved the sea, we created a nautical theme with lots of shells from the beach — including a gold-sprayed horseshoe crab shell — and added pine cones and large magnolia leaves,” Holmes said. “We sprayed the magnolia leaves and shells silver and gold, and made ornaments from shells, adding pearls, glitter and tiny stones. We wanted to make the large room as elegant as possible, and lightened it with silver and gold ribbon and bows. And of course, a large trimmed tree and wrapped presents.”

Mary Schlotter and her daughter, Krishtia McCord — who operate the Centerport design firm Harbor Homestead & Co. — decorated Rosamund Vanderbilt’s mirrored dressing room and the family’s breakfast hallway.

Using a dress-form mannequin, they added green boughs as a skirt. “Our friend, dress designer Lorri Kessler-Toth of Couture Creations, created a fitted turquoise-blue velvet cover for the dress-form torso,” Schlotter said. “We added a necklace of chandelier crystals and a pendant, and embellished the skirt with teal ornaments, champagne ribbon, and filigreed poinsettia leaves. This is a dressing room, so we created a Christmas dress,” added Schlotter. They also added chandelier crystals and champagne poinsettia leaves to the bough that decorates the mantelpiece on the marble fireplace. The crystals on the mantel complement those that hang from the sconces in the mirrored, hexagonal dressing room.

Finally, The Centerport Garden Club decorated the dining room and Mr. Vanderbilt’s bedroom, and the Honey Hills club decorated Mrs. Vanderbilt’s bedroom.

The Suffolk County Vanderbilt Museum, 180 Little Neck Road, Centerport will give guided tours of the decorated mansion each Tuesday, Saturday and Sunday and each day during the week between Christmas and the New Year through Dec. 30. Special Twilight Tours will be given on Dec. 26 and 27, from 7 to 9 p.m. For more information, call 631-854-5579 or visit www.vanderbiltmuseum.org.