The Carolina hemlock is rare, only growing naturally in a restricted area of the Appalachian Mountains in the United States. Its natural habitat is rocky slopes and ravines at heights between 750-1200m asl, in the same areas as catawba rhododendron (Rhododendron catawbiense) and calico bush (Kalmia latifolia). Growing to heights up to 30 metres, the Carolina hemlock is smaller than the other North American species, resembling its close relative eastern hemlock in appearance.
Carolina hemlock has been grown in Finland only in the Forest Research Institute’s test plantations and at Mustila. There is a group of trees dating from the Arboretum’s early years in Alppiruusulaakso (Rhododendron Valley). In appearance they are like darker and more elegant versions of the eastern hemlock: the branches and crown droop in the same way but the trees themselves are smaller, with narrower crowns; the roots reach deeper, making the species ideal for woodland gardens.