What’s now an ad hoc landscape of parking lots and scruffy lawns could transform into the latest attraction on the National Mall. The US Department of Agriculture is planning to convert its grounds into an outdoor museum of cultivation. 

Rendering of the teaching garden and market shelter. Image by OLBN via NCPC.

One hundred years ago, the US Department of Agriculture maintained a world-class arboretum on the Mall. Before the McMillan plan, USDA split the grounds of the National Mall with the the Smithsonian and the Botanic Gardens. Well-loved by local residents, the arboretum was one of Washington’s must-see tourist attractions in the 1890s.

The Arboretum in transition on the National Mall in 1906. The half-finished Whitten Building is at the right.

After a big fight, all that remains from the period is USDA’s headquarters, the James Whitten Building. The 1908 building is the only office building on the Mall. It’s a big monumental edifice that’s closed to the public. It’s surrounded by a motor court, parking lots, and unexciting plantings. It’s a dull spot on “America’s Front Yard.”

That could change if USDA goes ahead with a plan to turn its grounds into a public place of of interpretation and outreach.

The Whitten Building site plan. The Mall is at the top (north). The bottom is Independence Ave. Image by OLBN via NCPC.

Along the Mall, new landscaping by OLBN will make the ceremonial entrance more attractive. On the west side, a garden of heirloom plants for pollinating insects will surround a future memorial to black patriots. On the east side of the building, a new landscaping will expand the demonstration garden added in 2009.

Near the Smithsonian Metro station, the design proposes a market shelter clad in wood and bronze, on axis with the Beaux-arts building. Already, a farmer’s market takes over the eastern parking lot on weekends. With the renovation, the space will become a permanent garden plaza.

Other parking lots along Independence Avenue will be repaved with attractive materials that allow water to percolate into the ground. Over time, the department says it will use these more and more for events like farm equipment display.

Independence Ave. street section, with improvements to keep trees healthy. Image by OLBN via NCPC.

All of the sidewalks will see reconstruction to green public spaces. Stabilized ground, new permeable surfaces, and stormwater retention cells will make growing trees in the area possible again. Along C Street SW, the project will create a timeline of agricultural technologies. A similar exhibit runs around the the Department of Transportation’s headquarters at the Navy Yard.

The security plan. Red is a vehicle barrier built into benches, hedges, and walls. Image by OLBN via NCPC.

The interpretive gardens are one aspect. Security is another reason for the renovation. Thankfully, the design tightly wraps attractive security barriers and fences close to the building. Rather than try to expand the security perimeter by absorbing the city around it, USDA secured a Level IV facility in a way that’s not just friendly, it attracts the right kind of activity.

Washington’s various design review boards have approved the design with minor improvements, specifically, eliminating parking spaces from the formal entrance on the Mall side and adding street trees.

The design is an excellent effort to create an inviting public realm while meeting the needs of federal agencies. Culturally, it brings the bureaucratic mission of the department into contact with the daily life of city folks. As the Southwest Ecodistrict develops and nearby properties change hands, the quality of these spaces will become more and more important to city life.

The USDA knows that biodiversity makes healthier crops than monocultures. This plan shows that USDA understands that the same rules apply to urban spaces. Hopefully, Washington will see more of this line of thought as agencies rebuild.