Rockland, a 600-acre farm on the Potomac River, north of Leesburg on Route 15, is open to visitors Sunday and Monday. (Libby Devlin)

In 1817, Gen. George Rust bought a 485-acre tract along the Potomac River north of Leesburg and began building a Federal-style home there. The rock outcrops that studded the land inspired the property’s name: Rockland.

Two centuries and five generations later, Rust’s descendants still own and occupy Rockland. But maintaining old homes is costly, and the current occupants are searching for new ways to generate revenue from the property so they can continue to keep it in the family.

Rockland is one of six picturesque Leesburg-area properties that will be open to visitors Sunday and Monday during Virginia’s Historic Garden Week. The Garden Club of Virginia uses proceeds from the event, now in its 84th year, to restore and preserve historic public gardens across the commonwealth.

Three other private homes along the Potomac River are also on the tour: River Farm, Murray Hill and Riverside on the Potomac. The grounds of the four riverside properties — including Rockland — comprise “Gardens Along the Potomac,” the theme of Leesburg’s portion of Historic Garden Week, which is sponsored by the Leesburg Garden Club and the Fauquier Loudoun Garden Club.

Oatlands and Morven Park, two of Leesburg’s best-known tourist attractions, anchor the tour. Portions of the gardens at Oatlands, which were first planted in the early 1800s, were recently restored with funding from the Garden Club of Virginia. Morven Park, the former home of Gov. Westmoreland Davis, features a Colonial Revival boxwood garden and an array of flowering trees.

Maintaining the historic properties has proved somewhat challenging for 21st-century owners.

“Money just flies out of here,” said Libby Devlin, a descendant of George Rust who moved to Rockland with her husband, Nicholas, two years ago because her mother needed help keeping up with the endless maintenance needs. “I’m just scrambling because I don’t want to have to sell it out of the family after being here all these generations.”

Although some of the Rockland acreage is still farmed, it doesn’t produce much revenue, Devlin said. She and her husband are trying to come up with creative ways of generating income from the property — “anything I can think of to keep it in the family” — to help offset the costs.

Rockland and four of the other properties on the tour bring in money by hosting weddings, one of which was scheduled to take place at Rockland the day before the garden tour. Devlin said last week that she planned to leave the wedding tent, tables and flowers in place to promote it as a wedding location to visitors on the tour.

The Devlins are also working with a vendor to tap into the relatively recent surge of interest in glamour camping, or “glamping,” in which campers luxuriate in tents equipped with amenities such as beds with mattresses, electric lights and bottles of champagne.

“I just booked a wedding for 2018, and the whole wedding party . . . [is] going to have their wedding night glamping with about 40 of their friends,” Devlin said.

Devlin’s brother-in-law created a nine-mile bicycle trail on the property, where a bike race was also scheduled to take place. Devlin said she hopes that similar events will provide another source of income for Rockland in the future.

Fortunately, Loudoun County has been “pretty good” about allowing such alternative uses of rural properties, Devlin said.

“If you want to keep these open spaces, you’ve got to allow people to find businesses they can do on their land to support the maintenance,” she said.

The Devlins have also been busy readying their gardens for the tour, some of which were started by Libby’s mother and grandmother. Her grandmother’s collection of different types of daffodils bloomed early this spring, Devlin said. Her mother planted wildflower gardens among the rock outcrops.

“The redbuds are blooming, the dogwoods are blooming,” Devlin said. “I don’t think I’ve ever seen the garden this pretty.”

For information on Historic Garden Week, go to vagardenweek.org.