The 60-foot by 60-foot Pansy Garden was designed in 1913 by landscape architect John Handrahan. It was the second of three garden rooms he created near the mansion between 1911 and 1916 for Mark Clark Thompson. Visitors entered the garden from the west terrace through a pair of wrought-iron and gilded gates. A marble walk led from the gates the garden's centerpiece, a six-foot high marble fountain that stood in a pansy-shaped basin. It is believed that pansies were Mary Clark Thompson's favorite flower, and in this garden, she filled 13 different beds exclusively with masses of mixed-color and solid-color pansies. Devoting an entire garden to a single flower at that time was a novelty. In the language of flowers, pansies suggest "remember me." This garden allows Sonnenberg's visitors the opportunity to remember Mary Clark Thompson's gifts to the community. The entrance to this garden are copies of gates at the Villa Pamphili Doria in Italy. Almost all of the pansies for Sonnenberg's gardens were grown in the greenhouses. The site's archives contain a number of vouchers, similar to this one, for the purchase of pansy seeds. After Mark Clark Thompson's death, the Pansy Garden remained intact until 1931, when the estate was sold to the United States government. The fountain was found in one of
the estate's storage sheds and restored in 1973. In 2009, the fountain's plumbing was restored, and an irrigation system was installed.