Culture
Winter hardy to USDA Zones 8-10. In St. Louis, grow in containers or tubs that are overwintered indoors or as year-round houseplants. Container plants may be grown as shrubs or trained as ornamental standards. Plants generally grow best when overwintering period is short. Since plants will tolerate some frost, consider leaving containers outside in fall until temperatures dip below 20°F and return containers to a protected outdoor as soon as temperatures permit in spring. Overwinter in a cool location (40s F) with moderate light and very little water or as a houseplant in a bright sunny but cool room with reduced water. Grows well in average, medium moisture soils in full sun to part shade. Oleander is native to dry Mediterranean stream beds, and established plants will tolerate some drought and poor soils. However, container plants seem to do best in fertile soils with good drainage. Water regularly but let plant soils dry out between waterings. Promptly deadhead spent blooms to prevent formation of non-ornamental seed pods. Cuttings may be taken in late summer. Prune lightly as needed to shape after flowering (late summer to fall).
Noteworthy Characteristics
Nerium oleander, commonly called oleander, is an upright, rounded evergreen sub-tropical to tropical shrub that is valued for its abundant, fragrant, summer to fall flowers. Purple, pink or white five-petaled funnel-shaped flowers in clusters (terminal cymes). Narrow, willow-like, linear-lanceolate, glossy dark green leaves (to 5” long) have distinctive midribs. All parts of this plant are poisonous if ingested. Plant saps can cause allergic skin reactions in some people. Smoke from burning plant material can also be quite toxic. May be trained as a standard. Many cultivars are available in commerce with single or double flowers and in dwarf (2-4’ tall), medium (5-8’ tall) and large (9-20’ tall) plants. Sometimes also commonly called rosebay.
Genus name comes from the classical Greek name.
Specific epithet comes from the Italian oleandro for its olive-like leaves.
'Luteum Plenum' has clusters of semi-double to double, creamy yellow, ruffled flowers with a yellow throat. It grows 4 to 9 ft. tall and wide.
Problems
Watch for mealybugs, aphids and scale. Caterpillars may chew on the foliage. Remove and destroy any leaves damaged by leaf spot.
Uses
Container plant for sunny decks, patios and other locations around the home. In Zones 8-10, these plants are used in a variety of landscape applications including hedges, screens, foundation plantings and borders.