The rose garden is built in a circular shape to join the curving pergola with the north side of the new garden. The east and west sides are planted with American boxwood hedges, while the south side of the garden opens to terraced stone steps leading to the putting green. The garden is designed with a round bed in the center, encircled by four crown-shaped and eight crescent-shaped beds along the outside edge. The beds are divided by paths, which are patterned with brick and stone inlays. Mahogany benches, custom-built for Mrs. Post, are placed under the shade of the pergola for guests to relax and enjoy the view before them.

Each bed in this garden is planted with a separate variety of floribunda roses, which flower in May and are in bloom with the climbing roses that scale the pergola. Long after the climbing roses are finished, the floribundas continue to bloom through the summer, and sweet alyssum is added to line the edges, fragrancing the entire garden. In April, before the roses come into bloom, a different variety of Emperor tulips blooms in each bed to complement the early flowering shrubs surrounding the rose garden. The center bed, lined with a tightly trimmed English boxwood hedge and filled with seasonal flowers, is the site of Mrs. Post’s memorial monument.