Arboretum collections are: the Native Plant Collection, the Caroline Black Garden, the Connecticut College Campus, and the Greenhouse. The underlying bedrock of granite, schist and gneiss was scoured by glaciers about 26,000 years ago.[1] The resulting glacial till has produced a brown soil of stony fine sandy loam texture. The dominant soil association on well-drained hills is Charlton-Chatfield complex. Hollis series occurs where the soil is less than 50 cm thick. A localized silt deposit in the southern area is mapped as Narragansett series. Poorly drained soils include Ridgebury, Leicester and peaty Timakwa series.[2]
The Native Plant Collection of 8 ha (20 acres) was established in 1931, and displays trees and shrubs native to eastern North America and hardy in New London. It contains 288 taxa, including trees, shrubs, and woody vines indigenous to the forested region of Eastern North America, such as shadbush, dogwood, azaleas, mountain laurel, giant rhododendron, sourwood, sweet pepperbush, and evergreens and conifers. Of particular interest are:
The Lincoln and Lillian Dauby Gries Conifer Collection (est. 1988), featuring 1.2 ha (3 acres) of conifers: firs, spruces, hemlocks, junipers, pines, etc., and a variety of native shrubs.
The Nancy Moss Fine Native Azalea Garden (est. 1978), featuring 15 species and natural hybrid Azaleas (Rhododendron spp.).
The Josephine Hooker Shain Mountain Laurel Garden (est. 1985), featuring cultivars of mountain laurel (Kalmia latifolia), many of which are the work of Dr. Richard Jaynes.
The Caroline Black Garden contains a mature collection of ornamental trees, shrubs, and grasses from across the world, including 187 different woody taxa such as azaleas, Crimson Queen Japanese maple, sourwood (Oxydendrum arboreum), Japanese stewartia, fragrant viburnum, weeping cherry, and many other specimens.
The 280 m2 (3,000 square foot) Greenhouse includes a tropical house, a cactus collection, and an experimentation area.
The College Arboretum is also host to the biannual Arbo-Fest. Local and student bands can be found performing next to the lilly pond for the college students. Arbo-Fest is held once in the fall and once in the spring.
