Edward McIlhenny introduced numerous varieties of azaleas, Japanese camellias, Egyptian papyrus sedge and other rare plants to the Island's natural landscape.
Heathdale - ericaceous and Appalachian Plants, including Catawba and Rosebay rhododendrons (Rhododendron catawbiense and R. maximum), azaleas (Rhododendron spp.), dog-hobble (Leucothoe fontanesiana), mountain laurel (Kalmia latifolia), as well as hemlock (Tsuga canadensis, T. caroliniana, and T. sieboldii), dogwoods (Cornus spp.
Heath plants common to this ecology include mountain-laurel, Kalmia latifolia, various blueberries, genus Vaccinium, huckleberries, genus Gaylussacia, sourwood (or sorrel-tree), Oxydendron arboreum, and azaleas and rhododendrons, genus Rhododendron.
The main feature of the park is its rich forest of tall species; a dense forest, its atmosphere populated by Cryptomeria, Sequoia, Picconia azorica and the local Azorean Heather, its paths lined with Azaleas (Rhododendron), tree ferns (Sphaeropteris cooperii), Agapanthus and Camelias (Camelia japonica).
The collection of specimen trees and shrubs include towering American White and English Oaks, lindens, tulip trees, bald cypress, and Chinese Golden Larch, as well as different species and cultivars of azaleas, lilacs, viburnums, hollies, weeping cherries and rhododendrons.