Oleanders (Nerium oleander) are a mainstay of Mediterranean gardens, widely used for screen planting, on hillsides and alongside roads. Flowering in summer, the large open flower clusters can be single or double, and come in many colours including white, pink, red and peach. Upright stems are clothed with evergreen leaves which are long, slender, and an attractive shade of silvery-green.
Every part of the oleander plant is extremely poisonous if ingested and consuming even a small amount can be fatal. While the strongly bitter taste of oleander makes it unpalatable, it's wise not to grow oleanders where there are young children and pets. While oleander is toxic only if consumed, contact with the foliage may cause skin irritations. Wearing gloves when handling oleander is strongly advisable, along with thoroughly washing hands and exposed skin after handling or pruning.
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- Planting oleander
- Caring for oleander
- Propagating oleander
- Growing oleander: pests and problem-solving
- Oleander varieties to grow
Where to grow oleander
Oleanders are frost tender, so grow them outside only in a very sheltered, frost free spot in full sun, or indoors in a conservatory, porch, or greenhouse. Alternatively, grow oleanders in pots so you can move them under cover for winter.
Plant size is limited by the size of pot it's growing in, and will vary according to pot size. As a rough guide, oleanders in pots grow in the region of a 1m high and 60cm wide, while oleanders planted in the soil of a conservatory or outdoors could grow to around 1.5-1.8m high, with a slightly narrower spread.
How to plant oleander
Plant oleander in a good-sized pot using a soil-based potting compost (such as John Innes no. 3) mixed with a third of coarse grit or perlite to ensure good drainage. Stand the pot where there’s no danger of waterlogging – inside, this can be on a large saucer of pebbles to protect surfaces, while outside the pot should be raised just off the ground if standing on paving. Remember to wear gloves when planting oleander, as even the roots are poisonous.
How to care for oleander
Oleanders need regular watering from spring to autumn to keep the compost evenly moist, and it’s especially important that plants don’t go short of water in spring when the flower buds are forming. In winter, reduce the frequency of watering as growth slows. Feed with a liquid fertiliser every two weeks or so from late spring to early autumn.
Falling flower buds is a sign of the oleander drying out while the flowers were forming. Make sure your oleander doesn't go short of water during the growing season.
Every spring, repot oleanders, moving up to the next size of container. If plants are already in large pots, top-dress by gently scraping off the top 3-5cm of compost and replacing it with fresh, soil-based potting compost. Wear gloves and protect your arms by wearing long sleeves.
How to prune oleander
Pruning oleander bushes isn’t essential but is often necessary to reduce plant size, especially if moving from outdoors in summer to overwinter under cover. Ideally prune in late winter or early spring.
Start by removing any dead or damaged growth, then thin out crowded shoots. Cut back flowered shoots by half and remove a few centimetres of new shoot tips to encourage bushy growth. When pruning, remember that oleander poison runs through all parts of the plant so do wear gloves, as well as long-sleeved clothing to avoid contact with the skin. Put oleander prunings in your garden waste collection – don’t burn them, as even the smoke produced by burning oleander contains toxins.
How to propagate oleander
Take cuttings in mid to late summer. Select leafy non-flowering shoots and take cuttings around 10cm long, using a sharp knife to cut just below a leaf joint. Dip the base in hormone rooting powder and place in pots of seed and cuttings compost mixed with an equal volume of perlite or sharp sand. Alternatively, place cuttings in a jar of water then into compost when roots have developed. Discard the jar after use in case of contamination with oleander poison.
Oleanders can be grown from seed, picked when the seed ripens in autumn. Sow immediately into moist compost, prepared as above. Remember to wash your hands after handling the seed.
Pests and diseases
Oleander plants growing under cover are more prone to pests than those growing outside. Be vigilant and check regularly for pests such as scale insect, spider mites and mealybug.
Plants are likely to be reluctant to flower if there’s not enough good light. Move to a sunny spot for a better chance of flowering.
Flower buds that fall before opening are caused by the oleander drying out while the flowers were forming. Make sure your oleander doesn't go short of water during the growing season.
Yellowing foliage is a sign that plants are getting too much water.
Advice on buying oleander
- Oleanders are toxic to humans and pets – think carefully before you buy one
- Oleanders come in a wide range of varieties although plants are usually sold just by colour rather than name. White, red and pink-flowered forms are most widely available. Most oleanders have plain silvery-green leaves although variegated forms may be found
- Oleanders are available from a wide range of garden centres and nurseries, but you will find more choice at specialist nurseries
Where to buy oleander
Oleander varieties to grow
Nerium oleander ‘White’ – pure white five-petalled flowers are borne in clusters on the ends of branches, from the middle of summer to mid autumn. Evergreen, grey-green lance-shaped leaves. Height x Spread: 3m x 3m
Nerium oleander ‘Red’ – vivid cerise flowers show off particularly well against the evergreen greenish-grey foliage, with blooms borne for a long period during summer to mid autumn. H x S: 3m x 3m
Nerium oleander ‘Pink’ – rich pink five-petalled blooms are freely borne in summer and autumn, making a striking contrast to grey-green evergreen leaves. H x S: 3m x 3m
Frequently asked questions
Is oleander poisonous to the touch?
Oleander is poisonous only when ingested, although contact with the skin may cause irritation. All parts of the oleander plant are toxic so always wear gloves and clothing to protect your skin when handling oleander, and particularly when pruning, as that is when contact with the sap is most likely.
Can you grow oleander outside?
Oleander is rarely suitable for growing outside all year round in the UK, because it's frost tender and therefore likely to die when temperatures dip below freezing. Only in the very mildest of areas is it worth trying to grow oleander out of doors, but it's a huge risk and you're best growing oleander in a pot which you can move under cover in autumn.