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How to Grow Oleander

Nerium oleander

Perennial

Oleander is a stunning Mediterranean shrub with clusters of fragrant flowers from summer to autumn. In the UK, it needs a warm sheltered spot or container growing with winter protection. All parts are highly toxic — wear gloves when handling. Feed regularly during the growing season and water freely in summer.

Yearly Lifecycle

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JanFebMarAprMayJunJulAugSepOctNovDec
Bud Break Spring Growth Flowering Growing

Care Essentials

Feed fortnightly with a high-potash liquid fertiliser from spring to early autumn when in active growth.

Watch For

  • Scale insects
  • Mealy bugs
  • Oleander leaf scorch
  • Spider mites

Track your Oleander care schedule — pruning, feeding, and seasonal tasks

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Care Requirements

☀️ Light

Full sun — at least 6 hours direct sun per day.

Oleander thrives in maximum sunlight. In the UK, choose the hottest, sunniest wall available — ideally south- or south-west-facing. Insufficient sun reduces flowering severely.

💧 Watering

Moderate in summer; very sparse in winter.

Water freely during the growing season but allow the compost to partially dry between waterings. Reduce to almost nothing from autumn onwards — overwatering in cool conditions is the main cause of death.

🌱 Fertilizing

Balanced feed in spring, high-potash from summer onwards.

Apply a general balanced fertiliser in spring to support new growth, then switch to a high-potash liquid feed every two weeks once flower buds appear to maximise bloom.

✂️ Pruning

Prune after the main flowering flush, typically late summer.

Cut flowered shoots back by up to half to encourage bushy growth and a second flush. Always wear gloves — the sap is toxic. Remove dead, weak, or crossing stems at the same time.

❄️ Overwintering

Frost-tender; bring containers inside or protect wall plants with fleece.

Oleander is hardy only to about -5°C. Move pots to a frost-free greenhouse, conservatory, or cool indoor space before the first frosts. For wall-trained plants, drape horticultural fleece over the plant during cold spells and remove once temperatures rise.

Growing Tips

All Parts Are Toxic

Every part of oleander — leaves, stems, flowers, and sap — is highly poisonous if ingested. Always wear gloves when pruning or handling, and never burn prunings as the smoke is also toxic.

Drought-Tolerant Once Established

Oleander is extremely drought-tolerant once its roots are established. Reduce watering significantly in autumn and winter to avoid root rot.

Prune After Flowering

Cut back flowered shoots by up to half after the main flush of bloom to encourage bushy growth and a second flush. Always wear gloves.

Winter Protection in the UK

Oleander is frost-tender, hardy only to about -5°C. Move containers under cover before the first frosts, or protect wall-trained plants with horticultural fleece during cold spells.

Pests & Diseases

Pest Oleander Aphid

Identification: Clusters of bright yellow aphids on new shoot tips and flower buds, causing distorted growth and sticky honeydew.

Organic treatment:
  • Blast off with a strong jet of water.
  • Apply insecticidal soap or neem oil spray, repeating weekly.
  • Encourage natural predators such as ladybirds and lacewings.
Chemical treatment:
  • Spray with a systemic insecticide containing acetamiprid or thiacloprid.
Pest Scale Insects

Identification: Brown or white waxy bumps on stems and undersides of leaves. Plants weaken and produce sooty mould.

Organic treatment:
  • Scrub off with a soft brush dipped in soapy water.
  • Apply neem oil or insecticidal soap to affected areas.
Chemical treatment:
  • Use a systemic insecticide; repeat as directed on label.
Pest Mealybugs

Identification: White fluffy wax deposits in leaf axils and on stems; sticky honeydew follows.

Organic treatment:
  • Dab individual colonies with a cotton bud soaked in methylated spirits.
  • Apply neem oil or insecticidal soap spray.
Chemical treatment:
  • Spray with a systemic insecticide containing imidacloprid.
Disease Oleander Leaf Scorch Xylella fastidiosa

Symptoms: Leaf margins turn yellow then brown, scorching progresses inward; shoot dieback follows. Unlike drought scorch, it spreads progressively through the plant.

Treatment: There is no cure. Remove and destroy affected plants immediately to prevent spread. Do not compost.

Prevention: Buy certified disease-free stock. Avoid wounding plants unnecessarily and disinfect tools between plants.

Disease Sooty Mould Various fungi (e.g. Capnodium spp.)

Symptoms: Black powdery coating on leaves and stems, following honeydew deposits from aphids, scale, or mealybugs.

Treatment: Wipe off with a damp cloth. Treat the underlying pest infestation to remove the food source.

Prevention: Control sap-sucking pests promptly; ensure good air circulation around plants.

Log Oleander in your garden — track growth, care, and harvests year after year

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