At only 5 hectares,  Orchard Hill is a small but important part of the arboretum. The coolness and part shade of the site influenced Douglas Cook to plant cool loving species there such as Picea, Ilex, and Abies.

Planting in Orchard Hill began in the late 1950s. The Homestead Garden overlooks the lower basin, which was the original site of Cook’s orchard and cherry plantings. Later plantings of Magnolia and other spring flowering trees herald the start of spring each year.