Oleanders are a mainstay of Mediterranean gardens, widely used for screen planting, on hillsides and alongside roads. Flowering in summer, the large open 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 and consuming even a small amount can be fatal, so it’s wise not to grow oleanders where there are children and pets. The foliage may cause skin irritations. Wash hands thoroughly after handling or pruning, and ideally wear gloves.
How to grow oleander
Oleander, Nerium oleander, is a tender shrub and must be grown where temperatures never dip below freezing, so in the UK it’s only suitable for growing outside in the mildest areas. Usually, oleanders are grown in pots in a protected spot such as a conservatory, porch, or greenhouse, but they’re not suitable for warm centrally heated rooms. Oleanders can go outdoors for the summer months.
Buy and plant oleander bushes in spring or summer. Plant in a good-sized pot using a soil-based compost and place in a well-lit spot under cover away from central heating, or plant outdoors in a sunny, sheltered spot in mild areas only as oleanders won’t tolerate frost. Water regularly and feed during summer. Repot annually or top-dress, in spring.
Growing oleander: jump links
- Planting oleander
- Caring for oleander
- Propagating oleander
- Growing oleander: pests and problem-solving
- Oleander varieties to grow
Where to grow oleander
Good light is essential for oleanders to produce flowers. Indoors, site your oleander in a conservatory, porch, or cool room in bright light or outside in a sheltered spot that gets sun for all or most of the day.
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.
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 flower buds are forming. During winter, reduce the frequency of watering as growth slows. Feed with a liquid fertilizer every two weeks or so from late spring to early autumn.
Pruning oleander bushes isn’t essential but is often necessary to reduce the plant size, especially if moving from outdoors in summer to overwinter under cover. Ideally prune in late winter or early spring but pruning can be done in autumn if necessary. 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 un-flowered shoot tips which will encourage bushy growth.
Every spring, repot oleanders growing in pots, moving up to the next size of container. If plants are already in large pots, top-dress by gently scraping off the top 3-5 cm of compost and replacing with fresh soil-based potting compost.
How to propagate oleander
Take cuttings in mid to late summer. Select leafy non-flowering shoots and take cuttings around 10 cm 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 & cuttings compost mixed with an equal volume of perlite or sharp sand. Cuttings also root readily when stood in water and can then be potted into compost when roots are well developed.
Oleanders can also be grown from seed. Pick the ripe seed in autumn and sow immediately into moist compost as above.
Growing oleander: problem solving
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, red spider mite and mealybug: under cover, combat pests with a biological control.
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.
Growing oleander: buying advice
- Oleanders are toxic to humans and pets – think carefully before you buy one
- Always choose a healthy plant with no signs of pests or damage
- 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
Oleander, Nerium oleander, comes 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.
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 metre high and 60cm wide, while oleanders planted in the soil of a conservatory or out of doors could grow to around 1.5-1.8m high with a slightly narrower spread.