The South Lawn follows the naturalistic landscape style popular in England in the late 18th century. Once affording a view across the Potomac River, its first century was marked by the presence of livestock. Tudor Place’s original owners grazed sheep and cows on the lawn’s lower section. Armistead Peter, Jr., their great-grandson and the estate’s third owner, recalled that cows belonging to other local landowners had to be driven off the grassy expanse in the late 1800s. A Peter family home movie from the early 20th century shows the lawn being cut by a horse drawn mowing machine.
The area is surrounded by a natural landscape filled with many historic native trees and shrubs. Planted specimens include Cedrus deodara (deodar cedar), Quercus alba (white oak), American Highbush Cranberry (Viburnum trilobum), Ilex opaca (American holly), Cercis canadensis (Eastern red bud), Clematis virginiana (virgins bower) and more. In the west island, a weeping boxwood dating to 1805. The grove of American holly's in the south center of the lawn descends from the original holly, planted by Martha and Thomas Peter.
One tree in particular tree - Liriodendron tulipifera (tulip poplar), located east of the center of the lawn, is estimated to be more than 200 years old. This tree was chosen in 2002 by the America the Beautiful Fund as the Millennium Landmark Tree for the District of Columbia. Its low lying branches indicate that it matured in an open area. Most tulip poplars grow upright and tall, flowering only at the top third; on this one, blossoms cover the entire tree. Tulip poplars in the southwest and southeast corners are perimeter plantings of a similar age.