While much of the country is waiting for a few buds to renew the promise of spring, the South blooms with a palate of pastel azaleas, dogwood and roses. What better time to celebrate the region's gardens, culture and architecture?

And so Southern cities and societies fill March and April calendar pages with occasions ranging from decorous to down-home. Here's a selection of events; be sure to call ahead for more information and room reservations.Charleston, S.C., has just begun its month-long series of walking tours of historic homes and handsome gardens. There are afternoon and evening tours of 8-to-10 private homes. There will be 11 tours plus weekly oyster roasts, between now and April 14. $25 for each tour or event; proceeds to Historic Charleston Fund. For information or tickets, contact the fund, 108 Meeting St., Charleston, S.C. 29401; (803) 722-3405.

Savannah, the city Union Gen. William Sherman considered too beautiful to burn, celebrates its 56th annual Tour of Homes and Gardens from April 4-8. There will be six walking tours, including one focusing on 19th-century churches. There will also be seminars on cooking, flower arranging, historic gardening and renovation, a shrimp boil, a barbecue and special group lunches at two city favorites, Mrs. Wilkes Boarding House and Elizabeth's. Walking tours are $15 each; other prices vary. Contact Savannah Tour of Homes and Gardens, 18 Abercorn St., Savannah, Ga. 31401; (912) 234-8054.

Later in the month, Savannah offers a more localized tour of the walled gardens in the residential area known as North of Gaston Street - hence the name of the tour, Hidden Gardens of the NOGS. April 19-20; tickets are $12.50 and include refreshments. Contact Garden Club of Savannah, 435 E 56th St., Savannah, Ga. 31405; (912) 238-0248.

The month of April is the time to sample the beauty of the azaleas and other spring annuals at Bellingrath Gardens and Home, a few miles south of Mobile, Ala. For hours and fees, contact the gardens at 12401 Bellingrath Highway, Theodore, Ala. 36582; (205) 973-2217.

Biltmore, the impressive chateau built on a 25,000-acre estate outside Asheville, N.C., is celebrating a Festival of Flowers from April 6-May 5, 9 a.m.-5 p.m. daily. The mansion, built in the 19th century for the Vanderbilts, is spectacular; the grounds and adjacent winery notable. For fees and information, contact the estate at 1 North Pack Square, Asheville, N.C. 28801; (704) 255-1700.

Pilgrimages are devoted to maintaining the romantic legend of the Old South, featuring tours of plantation homes and the most elegant and carefully preserved city residences. Some tours include guides, some offer private guides at additional cost, but mostly, docents in each building or room provide the historical commentary. Pilgrimages include these:

Natchez, Miss., Spring Pilgrimage has six tours of five houses each. Now through April 7. One tour, $17, two or more, $15 each; children 6-17, half-price. Natchez Pilgrimage Tours, Canal at State St., P.O. Box 347, Natchez, Miss. 39121; toll-free (800) 647-6742, or call (601) 446-6631.

Historic Selma, Ala., Pilgrimage and Antique Show, Victorian and antebellum homes, March 22-24. Contact Selma-Dallas County Historic Preservation Society, P.O. Drawer D, Selma, Ala., 36702; (205) 875-7241.

Columbus, Miss., Pilgrimage includes something different: prep school students offering their historic research on a dozen of the town's more notable residents - in the town cemetery. Friendship Cemetery is said to be the site of the nation's first Memorial Day observance. The students' presentations, which are free, will be on nights when there are no candlelight tours of the homes. The tours, March 28-April 7, display a dozen homes; tours are $4 per home. Contact Columbus Historic Foundation, P.O. Box 46, Columbus, Miss., 39703; (601) 329-3533.

Eufala Pilgrimage and Antique Show is in its 26th year and displays Victorian and antebellum mansions and tea gardens. There are separate daytime and candlelight tours, April 5-7, and prices range from $3 to view a single home to $20 for an eight-home tour plus admission to an antiques show. There will also be candlelight tours and an outdoor art show in the historic district. Contact Eufala Heritage Association, P.O. Box 486, Eufala, Ala. 36072; (205) 687-3793.

Huntsville, Ala., Pilgrimage features nine houses and three churches. The buildings are divided into two tours; the price for one tour is $10, for both, $18. The tours take place April 13-14, and there will also be a tea the afternoon of the 13th that features early 19th-century recipes and silver service, with costumed hostesses; the tea is $5. Contact Huntsville Convention & Visitors Bureau, 700 Monroe St., Huntsville, Ala. 35801; (205) 551-2230.

There is no limit to the topics or events that Americans will celebrate. Springtime down South offers plenty of examples:

The boll weevil is worth a month-long exhibit at Montgomery's Old Alabama Town. The insect that nearly destroyed the cotton crop is featured in "The Boll Weevil: Just Looking for A Home," April 1-30 daily. Contact Mary Ann Neeley. Old Alabama Town, 310 Hull St., Montgomery, Ala. 36104; (205) 263-4355.