The Arboretum has developed a number of collections of plants that it features in beds throughout the gardens.

These collections include the Hardy Fern Collection; the Holly (llex) Collection; and the Arboretum's most notable collection of Azaleas, which are showcased mainly in the Jonsson Color Garden, but are also prominently displayed throughout the grounds. Naud Burnett II, the landscape and architect that completed the design and installation of the 6 1/2 acre color garden, used Azalea varieties to visually unify the garden. At the time the garden was established, there were only about 15 to 20 varieties of azaleas commonly available in the Metroplex. Today our collection contains about 2,800 specimens.

A new collection currently being installed is the Hardy Palm and Tropical Collection donated by the First Men's Garden Club of Dallas with Tom & Nancy Wilten. This collection will be display and trial of all the hardy palm species adaptable to our climate. This display is located behind the "Water Wall" feature in the Lay Ornamental Garden.