Rhododendron Catawbiense or Catawba Rhododendron
The Catawba rhododendron is one of the most important of the evergreen species. A native of Virginia, Carolina and Georgia, it is a shrub up to 2.5m (8 ft) high and in the land of origin also a small tree about 6m (20 ft) high with elongated, slightly wrinkled leaves about 10 cm (4 in) long, dark green above and pale green below. Theare borne in terminal clusters of as many as 15 blossoms in June. They are broadly bell-shaped and coloured purplish-lilac finely spotted with olive green inside at the base.
Most large-flowered evergreen rhododendrons have been derived from the Catawba rhododendron. It is generally crossed with the following species: Rhododendron arhoreum, mostly red; Rhodendron maximum, mostly white or pink; Rhodendron caucasicum, red; Rhodendron ponticum, reddish-violet. The resulting basic hybrids have yielded hundreds of different garden forms.
Cultivated rhododendrons are propagated chiefly by grafting. Used as rootstock in coastal regions is Rhodendron ponticum and in inland regions the hybrid ‘Cunningham’s White’. The rootstock should be transferred to the propagator about a month before grafting so that it will become acclimatized. The scions are taken and grafted in January or February, usually by whip or tongue grafting. The temperature in the propagator should be kept at about 20°C (68°F). When the scion and stock are firmly joined the scion is cut back and the grafted plants are transferred to a frame in June.