Oleander

Sun

Full sun gives the best flowering; light shade is tolerated but reduces blooms.

Water

Water deeply during establishment. Established plants tolerate drought, but flower better with occasional deep watering during prolonged dry weather; containers need more frequent watering.

Soil

Well-drained sandy, loamy or clay soil; tolerates alkaline soil and moderate salt exposure. Avoid permanently wet ground.

Height

6-20 ft (1.8-6 m), depending on cultivar and climate

Spread

6-12 ft (1.8-3.7 m)

Flowers

Late spring to autumn in warm climates; mainly summer in cooler areas. Flowers may be white, pink, red, salmon or pale yellow, depending on cultivar.

Foliage

Evergreen. Leathery, narrow, dark green leaves, usually arranged in pairs or whorls of three.

Growth

Fast in warm conditions with adequate water.

Care needed

Medium

• Deer resistant
• Drought tolerant
• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   5 ft (1.5 m)

3. After 2 years

   9 ft (2.6 m)

4. After 3 years

   12 ft (3.6 m)

5. After 5 years

   13 ft (3.9 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Invasive in

Australia

Growth rate

Fast

• Water newly planted shrubs deeply whenever the root zone begins to dry; allow excess water to drain away.
• Apply a 2-3 in (5-8 cm) mulch layer over the roots, keeping it away from the stems.
• Feed container plants with a balanced flowering-plant fertiliser during active growth, following the label; established plants in the ground rarely need feeding.
• In cold regions, grow in a pot and move it into a bright, frost-free place before autumn frosts; water sparingly through winter.
• Wear gloves when handling or pruning, keep cuttings away from animals, and never burn the prunings.

Pruning. In late winter or early spring, remove dead or frost-damaged wood and thin crowded stems at their base. Shorten selected branches to control size rather than repeatedly shearing the whole shrub, which removes flowering shoots.

Late winter

Inspect for frost damage and prune once the risk of severe frost has passed.

Spring

Plant into warming soil after frost risk has passed, or repot container plants if root-bound.

Late spring

Acclimatise overwintered plants gradually to outdoor sun and begin feeding container plants.

Summer

Water containers regularly and check new shoots and leaf undersides for aphids, scale and caterpillars.

Late summer

Take semi-ripe cuttings if you want plants matching the parent; handle sap with gloves.

Autumn

Move pots under bright, frost-free shelter before frost arrives in cold regions.

Winter

Keep sheltered plants on the dry side without allowing the root ball to dry out completely.

• Use as an informal flowering screen along a sunny boundary where there is room for its mature width.
• Place a compact cultivar in a large courtyard container that can be moved under winter shelter.
• Combine with lavender, rosemary and rockrose in a sunny Mediterranean-style border.
• Use as a tall flowering backdrop in warm coastal gardens, away from play areas and livestock.

Garden styles it suits: Mediterranean, Modern Mediterranean, Coastal, Modern courtyard, Luxury resort and Desert / xeriscape.

Plant it with: Lavender, Rosemary, Rockrose, Santolina, Agapanthus and Olive.

Wildlife: Flowers attract some visiting insects, but provide little or no nectar and are not a strong choice for pollinator planting. Dense shrubs can provide cover for small birds.

• Aphids and scale insects: inspect shoots and leaf undersides; wash off aphids and treat persistent infestations with a labelled insecticidal soap or horticultural oil, avoiding hot sun.
• Oleander caterpillars, especially in the southeastern United States: inspect regularly and remove infested shoots with gloves, or use a locally approved caterpillar treatment while larvae are small.
• Oleander leaf scorch: this bacterial disease causes progressive yellowing, scorched leaf margins and branch death. There is no cure; seek local diagnosis and remove severely affected plants.
• Frost damage: leaves and stems may blacken or die back. Protect container plants before frost and wait until spring growth reveals living wood before cutting back.

Highly toxic to people, cats, dogs and horses. All parts, including flowers, leaves, stems, roots and dried clippings, contain cardiac glycosides; ingestion can cause fatal heart rhythm disturbances. Sap can irritate skin and eyes. Never burn prunings or use branches as cooking skewers, and keep clippings out of animal feed and drinking water. Suspected ingestion requires immediate medical or veterinary advice.

Where it spreads. Can spread along waterways and disturbed ground in warm regions; it is regarded as an environmental weed in parts of Queensland and New South Wales, Australia. Check local weed guidance before planting near natural areas or watercourses.

• Yellow oleander (Cascabela thevetia)

  Has narrower, usually spirally arranged leaves, yellow funnel-shaped flowers and fleshy fruits rather than oleander's paired slender seed pods. It is also highly poisonous.

• Desert rose (Adenium obesum)

  Has a swollen succulent trunk and shorter, broader leaves clustered near branch tips; oleander has woody stems without a swollen base.

• Rhododendron (Rhododendron spp.)

  Most have broader, alternately arranged leaves and conspicuous terminal flower buds; oleander has narrow leaves in opposite pairs or whorls, often with long seed pods after flowering.

Nerium comes from nerion, the ancient Greek name for oleander.

Propagation. Root semi-ripe stem cuttings in summer in a free-draining medium with gentle warmth. Cuttings retain the parent's flower characteristics; seed-grown plants may differ. Wear gloves and keep all propagation material away from children and animals.

Accepted botanical name

Nerium oleander

In the US and Canada

Introduced in the lower 48 states, Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Afghanistan, Albania, Algeria, Baleares, Corse, Cyprus, East Aegean Is., France, Greece, Gulf States, India and Iran.

Measured

Soil pH 5.5 to 7.8. Average height 366 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.