Oleander (Nerium oleander) is a remarkably resilient plant, but cultivar selection is paramount for a thriving privacy hedge. While all oleanders prefer warm, Mediterranean-like climates (USDA zones 8-10), some offer enhanced cold tolerance. For marginal areas in zone 8, consider hardier cultivars like the white-flowered 'Hardy Red' or 'Austin Pretty Limits'. For standard warm climates, popular dense choices include 'Sister Agnes' (single white) or 'Calypso' (cherry red). Dwarf varieties, such as 'Petite Pink' or 'Petite Salmon', are unsuitable for a privacy screen as they typically only reach 4 feet in height; instead, opt for standard cultivars that will achieve the desired 8-15 foot hedge height.
From the plant's perspective, successful establishment is rooted in its new environment. Oleanders are notoriously adaptable to poor soils but absolutely require excellent drainage. They will suffer and develop root rot in consistently waterlogged soil. They thrive in full sun, requiring a minimum of six hours of direct sunlight daily for dense foliage formation and prolific flowering. Insufficient sun leads to a leggy, open growth habit, defeating the privacy purpose. When planting, space the shrubs 4 to 6 feet apart, center to center. This spacing accounts for their mature width, allowing the plants to grow together and form a solid, interwoven barrier without excessive competition for water and nutrients at the root level.
Although drought-tolerant once established, consistent watering is critical for the first growing season to develop a deep and extensive root system. Water deeply 2-3 times per week, allowing the soil to dry slightly between waterings. A 3-4 inch layer of organic mulch around the base of each plant (keeping it away from the main stem) will help retain soil moisture, regulate root temperature, and suppress weeds. Avoid high-nitrogen fertilizers, which promote soft, weak growth and reduce flowering. Instead, in early spring, apply a slow-release, balanced fertilizer or one with a higher phosphorus content to encourage strong root development and abundant blooms, which are a hallmark of the plant.
Pruning is essential for cultivating a thick, lush hedge. Oleanders bloom on new growth, so the best time to prune is after their main spring flowering period, typically in late summer or early fall. Avoid late fall pruning, as new, tender growth can be damaged by early frosts. To encourage dense, bushy growth from the base, perform renewal pruning annually or biennially by selectively removing up to one-third of the oldest and tallest canes at ground level. This technique allows more light and air into the center of the plant, stimulates new growth from the base, and maintains the hedge's vigor and foliage density from top to bottom, ensuring complete privacy.
