The arboretum's master plan was developed from 1996-1999 by Sasaki Associates. Specific plans for landscape and botanic gardens and their associated facilities were completed in 2002 by MTR Landscape Architects LLC, and the first tree, a white oak (Quercus alba) was dedicated in 2005. A donation of $10 million was needed to begin the construction of the Arboretum and on May 18, 2007, this donation was received from Charles H. "Skip" Smith. The construction of Phase I of the H.O. Smith Botanic Gardens, named in honor of Mr. Smith's father, was completed in fall 2009 and the gardens were officially dedicated on April 25, 2010.
In July 2014, the Arboretum finished construction of and opened the Childhood Gate's Children's Garden. It includes a limestone cave, stone amphitheater for events, and other attractions for children. The Children's Garden has many native Pennsylvania plants and is a microcosm of the regional landscape.