With 60-plus years of house and garden tours under their belts, the folks at the Historic Charleston Foundation know enough not to tamper with success. But they also know that successful tours mean repeat customers - visitors who plan their spring around coming to the Holy City to peek inside its historic private homes and intimate gardens - so resting on their laurels is not an option.

If you go

What: Historic Charleston Foundation's 67th annual Festival of Houses and Gardens

When: Daily through April 19

Where: Downtown Charleston homes, gardens and other venues around the Lowcountry, including churches, plantations and the harbor

Tickets and info: Call 722-3405 or go to www.historiccharleston.org/festival

"There are some tried-and-true things that we know are successful and that people tell us they have a great time at every year, but we do create new, customized tours every year," says Melissa Nelson, marketing and communications director for the foundation, whose 67th annual Festival of Houses and Gardens is under way through April 19. "We say that the house and garden tours are our flagship, but what makes it a festival is the concerts and the wine tastings and the luncheon lectures. Those things are part of what keeps it new every year."

No doubt, the formula is working: Nelson says a College of Charleston survey showed that the 2013 festival, along with the foundation's Charleston Antiques Show, had a $6.4 million economic impact on the community.

We asked Nelson to narrow down the wealth of festival events to five standouts: activities that are new or different this year or that simply always draw a crowd. Here are her suggestions:

Inspiring Gardens tours

Nelson says the Glorious Gardens Tours on Thursdays during the festival are perennial favorites, and this event gives visitors another opportunity to bask in the glory of April in local gardens. "The Inspiring Gardens tour goes to some different neighborhoods and gardens that we really haven't highlighted before," she says. The self-paced tour in Ansonborough will give visitors the chance to talk with some of the landscape designers and gardeners behind the beautiful spaces. When: 2-5 p.m. April 14 and April 19. Cost: $50.

Bluegrass Jamboree

"We've done bluegrass in the past, but never at the Music Hall," Nelson says. The bands Hungry Monks, YeeHaw Junction and the South Carolina Broadcasters will perform, and beer, wine and soft drinks will be sold during the intermissions between bands. When: 7-9:30 p.m. April 9, Charleston Music Hall. Cost: $35.

Plantation Picnic and Oyster Roast with Easter Egg Hunt

Drayton Hall Plantation is the setting for this event, and between the Easter egg hunt and the tours of Drayton Hall, there really is something for all ages. "We always hear from visitors that they plan their trip for the weekend of the oyster roast just so they can enjoy these specific oysters," Nelson says. "The Easter egg hunt has become really popular, too." (A similar event, minus the egg hunt, takes place at the Aiken-Rhett House downtown.) When: 4:30-7 p.m. April 18. Cost: $45 for adults; $20 for ages 6-12; free for kids under 6. Reservations required.

Craft Beer Tasting and History of Lowcountry Brewing

Wine tastings have become a staple of the festival, and this year a beer tasting joins the party. Local "beer bard" Timmons Pettigrew and Palmetto Brewery's Christopher Winn will lead the tasting of Palmetto craft beers at the foundation's offices at 40 East Bay St., overlooking the Battery. When: 5:30-7 p.m. April 4. Cost: $40. Reservations required.

House and Garden Tours

As Nelson says, these are the flagship of the festival. "We try every year to change the properties and change the order of the tours so that someone who comes the same dates every year will have a different experience every time," Nelson says. On each tour, guests can visit eight or more private houses, gardens and notable sites along the route. Guides are stationed at each site to provide information about it. When: 2-5 p.m. daily through April 19, with several candlelight tours offered as well. Cost: $50.