Landscape contractor Roger Cook brings host Kevin O'Connor to the United States Botanic Garden — it's at the base of the Capitol and serves as the nation's greenhouse boasting 4,000 living species and 26,000 different plants. Back at the project house, Roger finds garden designer Kevin Cordt and his crew bringing in steel edging, pea stone, and plant material for the new backyard garden. Inside, general contractor Mahyar Mahvi shows master carpenter Norm Abram how he's sealed the exposed brick and started the tile work on the second floor. Custom stair manufacturer Jeff Glass and his crew fabricate a laminated railing for the new curved staircase. Interior designer Kate Dieterich shows Norm a new linoleum flooring for the kitchen that's homeowner friendly — it comes in panels with a cork backing, and clicks together without glue. In nearby Anacostia, Kevin meets park ranger Eola Dance for a look at the ongoing restoration work at the Frederick Douglass National Historic Site. Upstairs in the back bedroom, flooring contractor Ralph Santos installs a traditional pre-finished strip oak floor.