The disease is more likely to occur when plants have been subjected to drought stress or damaged by severe freezes. Prune out all affected branches, making sure that no discolored tissue is left in the cross section. In general cultivars with thicker, dark-green, leathery leaves tend to be hardier to cold. Single flowers usually drop cleanly while spent double flowers may linger unattractively on the plant. On the other hand, most fragrant oleanders have double flowers.
Nurseries often sell oleanders by color rather than by name.
Algiers grows 5 to 8 feet tall. It is free blooming, with single, dark red flowers. Calypso is cold hardy and vigorous, growing 10 to 18 feet tall, with single cherry red flowers. Hardy Red is the hardiest cultivar, surviving even in some protected locations in the Piedmont, although it may suffer damage in some winters. The plants grow to 8 feet tall with very deep red, single flowers.