Selections of this species are superb landscape plants wherever they are winter hardy. These Mediterranean natives are tough as nails and combine spectacular flowers with hand- some foliage. Growing quickly to 320ft. tall and 412 ft. wide (depending on the selection), they naturally form billowing shrubs but are easy to train into single-trunked trees. They make outstanding windbreaks and tall screens and also do well in containers. Narrow, 4- to 12-in.- long leaves are dark green, leathery, and attractive in all seasons. Clusters of single or double, sometimes fragrant flowers in red, pink, salmon, yellow, or white appear at branch tips from spring to fall, depend- ing on the climate.
All parts of oleander plants are poisonous; deer don't browse them. Keep prunings and dead leaves away from hay or animal feed, and don't use branches for fires or barbecue skewers. Smoke from burning oleander branches can cause severe irritation to mucous membranes.
Dozens of named selections exist, some of which are described below. They typically grow about half as wide as tall. For the plant called yellow oleander, see Thevetia.
'Algiers'. Single dark red flowers. To 1012 ft. tall.
'Calypso'. Cold tolerant and vigorous with single red flowers. Grows 1018 ft. tall.
'Casablanca'. Profuse show of single white flowers. To 46 ft. tall.
'Franklin D. Roosevelt'. Single deep salmon flowers with yellow throat. Very hardy. To 10 ft. tall.
'Hardy Pink'. Single salmon-pink flowers. Probably the hardiest oleander, tolerating temperatures into the low teens without damage. Reaches 10 ft. tall.
'Isle of Capri'. Single light yellow blossoms. To 57 ft. tall.
'Lane Taylor Sealy'. Single, fragrant, light salmon blooms with a yellow throat. To 8 ft. tall.
'Little Red'. Single dark red flowers. Hardier than most. Compact grower to 34 ft. tall.
'Mathilde Ferrier'. Cold-tolerant, double yellow bloom, grows to 8 ft. tall.
'Morocco'. Single white blooms. To 57 ft. tall and wide.
'Mrs. George Roeding' ('Carneum Plenum'). Double, fragrant, salmon-pink flowers; fine-textured foliage. Slightly weeping form. Grows to about 6ft. tall.
'Petite Pink'. Single shell-pink blooms. To 34 ft. tall.
'Petite Salmon'. Single salmon-pink flowers. To 34 ft. tall.
'Ruby Lace'. Single, large ruby-red blossoms. Grows to 8 ft. tall.
'Sister Agnes' ('Soeur Agns'). Single white flowers. Vigorous grower reaches 1520 ft. tall.
'Sue Hawley Oakes'. Creamy yellow flowers with a yellow throat. Grows to 8 ft. tall.
'Sugarland' ('Hardy Red'). Single red flowers. More cold tolerant than most. Reaches 10 ft. tall.
Few plants are as adaptable to challenging growing conditions as oleanders. They are ubiquitous along Southern coasts, because they tolerate wind, salt spray, and sandy soil. Once established, they need little water; they'll also grow in poorly drained soil, be it acid or alkaline. Their only limitation is susceptibility to cold. Most selections will weather brief periods of 10F or a bit colder, but they may be killed to the ground. They will, however, usually resprout the following spring and bloom at the usual time. Older, established plants are hardier than young ones. In the Upper and Middle South, grow oleanders in containers and bring them indoors for the winter.
Regular pruning isn't necessary, but if you need to shape the plant or reduce its size, do so immediately after flowering. Avoid pruning within three months of the first expected fall frost. To renew old, unattractive, leggy plants, lop them nearly to the ground before new growth begins in spring.
Oleanders are usually pest free, but infestations of bright orange oleander caterpillars can defoliate entire plants; the damage typically isn't fatal. A new scourge called oleander leaf scorch has recently appeared in Texas. Caused by a bacterium spread by a sucking insect, this disease causes leaves to turn brown, then drop; eventually, the plant succumbs. Quickly remove and dispose of infected plants.