Oleander Care: Full Sun, Pruning and Pet Toxicity

Oleander (Nerium oleander) is a fast-growing evergreen shrub for full sun, heat and poor, dry soil, hardy in about USDA zones 8b or 9a through 10 or 11 depending on the source. It also needs a clear safety note: the ASPCA lists oleander as toxic to dogs, cats and horses, and UF/IFAS says all parts of the plant are toxic if ingested. Read that before you plant it anywhere animals or children roam.

USDA zones

8b–10 (Clemson); 9a–11 (UF/IFAS)

Sun

Full sun; few flowers in shade

Water

Very drought tolerant once established

Origin

Mediterranean

Soil

Wide range, pH 5.0 to above 8.3; good drainage

Size

5–19.5 ft tall, 6–10 ft wide (NC State)

Bloom time

Early summer to mid-autumn (Clemson)

Prune

Early spring

Pets

Toxic to dogs, cats and horses (ASPCA)

Zones and cold

The two southern extension sources disagree on the range, so treat the edges with caution.

NC State describes oleander as a rapidly growing, rounded, broadleaf evergreen shrub. If your winters regularly dip to freezing, this is a plant to look at carefully before you buy.

Sun and site

UF/IFAS says full sun is necessary for best flowering and for development of a full, fountain-shaped crown. In shade it will grow lanky and produce few flowers. NC State is a little gentler and says oleander prefers full sun to partial shade and well-drained, fertile soil.

Soil and water

UF/IFAS says oleander is tolerant of a wide range of soil types, grows well in sandy dry areas, and adapts to a pH range of 5.0 to more than 8.3. Once established it is very drought tolerant, but moist soil or irrigation stimulates growth (UF/IFAS). Clemson agrees that oleanders are very heat and drought tolerant once established. UF/IFAS also says established plants usually need no fertilizer because the species has low fertility requirements.

Size and spacing

NC State says oleander grows 5 to 19.5 feet tall and 6 to 10 feet wide. UF/IFAS gives 10 to 18 feet in height and 10 to 15 feet of spread for the standard shrub, and says that planted on five to seven-foot centers, a row of oleander makes a nice screen. For smaller spaces UF/IFAS names dwarf cultivars such as ‘Petite Pink’ and ‘Petite Salmon’, reaching about 4 feet in height and working well without pruning.

Pruning

Clemson says that since oleanders bloom in summer on new growth, prune them in early spring. NC State says to refrain from pruning after early fall, to avoid removing next year’s flower buds. UF/IFAS says suckers at the base should be pulled while they are young and succulent. See our oleander pruning guide for the cut-back options and the fall disagreement.

1. Early spring: prune. Oleander blooms on new growth, so prune before growth starts (Clemson).
2. While young: pull suckers. Basal suckers come away easily when young and succulent (UF/IFAS).
3. Early fall onward: stop. Do not prune after early fall, so you keep next year’s buds (NC State).

Flowers and varieties

Clemson says oleanders flower from early summer until mid-autumn, with large clusters of 2-inch single or double blossoms. NC State puts bloom from late spring to late summer, in colors from pink to peach to white. UF/IFAS says the double-flowered oleanders are the ones that tend to be fragrant. Propagate by seed or stem cuttings (NC State).

Common oleander problems

Grow these next

Oleander shares the sun-and-drainage logic of the lavender guide, another shrub that wants a bright, dry site. If you are weighing shrubs for a pet-friendly garden, our camellia guide and rosemary guide cover two the ASPCA lists as non-toxic to dogs, cats and horses.