Nerium oleander
Habit | shrub
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Height: | ⇕ | 2 m"m" can not be assigned to a declared number type with value 2. to 6 m"m" can not be assigned to a declared number type with value 6. |
Width: | ⇔ | 2 m"m" can not be assigned to a declared number type with value 2. to 5 m"m" can not be assigned to a declared number type with value 5. |
Lifespan: | ⌛ | perennial |
Origin: | ✈ | Medit. to China |
Poisonous: | ☠ | highly toxic, fatal |
Bloom: | ❀ | mid spring, mid summer, mid fall |
Exposure: | ☼ | sun |
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Water: | ◍ | moist, moderate, dry |
Features: | ✓ | flowers, drought tolerant |
Minimum Temp: | ☃ | -10°C14 °F <br />263.15 K <br />473.67 °R <br /> |
USDA Zones: | 9 to 11 | |
Sunset Zones: | 8-16, 18-31 |
Nerium > |
oleander > |
Oleander thrives best in warm summer climates where winters are mild. Growth is moderate/fast. Natural habit is broad with many stems, but training it to tree form is easy. It is very useful as windbreak, privacy screen, along roads, in tubs. The leaves are dark green and leathery, narrow, 5-21 cm long and 1-3.5 cm broad, and with an entire margin. Plant and leaves are attractive year round. There is a variegated form with golden margins on the leaves.
Flowers at the end of branches come in clusters, each flower is 2.5-5 cm diameter. The long bloom period from spring to fall is one of the reasons for its popularity, with the extreme drought tolerance being another. Many cultivars have scented flowers, coming in red, pink, white salmon and yellow. Double flowers are less common than single. Single flowers fall off after finishing, while double flowers turn brown and remain until trimmed off.
Oleander is an extremely poisonous plant if ingested. In case it is ingested, vomiting should be induced, and immediate treatment sought. Do not use trimmed branches for barbecues or fires.
Oleander (Nerium oleander, (pronounced /ˈnɪəriəm ˈoʊliː.ændər/),[1] is an evergreen shrub or small tree in the dogbane family Apocynaceae and is one of the most poisonous plants known. It is the only species currently classified in the genus Nerium.
It is native to a broad area from Morocco and Portugal eastward through the Mediterranean region and southern Asia to Yunnan in southern parts of China.[2][3] [4][5] It typically occurs around dry stream beds. It grows to 2-6 m tall, with spreading to erect branches. The leaves are in pairs or whorls of three, thick and leathery, dark green, narrow lanceolate, 5-21 cm long and 1-3.5 cm broad, and with an entire margin. The flowers grow in clusters at the end of each branch; they are white, pink, red or yellow, 2.5-5 cm diameter, with a deeply 5-lobed corolla with a fringe round the central corolla tube. They are often, but not always, sweetly scented. The fruit is a long narrow capsule 5-23 cm long, which splits open at maturity to release numerous downy seeds.
Oleander grows well in warm subtropical regions, where it is extensively used as an ornamental plant in landscapes, parks, and along roadsides. It is drought tolerant and will tolerate occasional light frost down to -10°C. [5] It is commonly used as in landscaping freeway medians in California and other mild-winter states in the Continental United States because it is easily maintained—it is deer resistant and tolerant of poor soils and drought. Oleander can also be grown in cooler climates in greenhouses and conservatories, or as indoor plants that can be kept outside in the summer. Oleander flowers are showy and fragrant and are grown for these reasons. Over 400 cultivars have been named, with several additional flower colours not found in wild plants having been selected, including red, purple, pink and orange; white and a variety of pinks are the most common. Many cultivars also have double flowers. Young plants grow best in spaces where they do not have to compete with other plants for nutrients.
Oleander is one of the most poisonous plants in the world and contains numerous toxic compounds, many of which can be deadly to people, especially young children.
A popular greenhouse pot plant that can be grown outdoors in the summer, it can be grown outdoors all year round in the milder areas such as Cornwall[1, 260]. A very ornamental plant[1], there are many named varieties[200, 260]. Plants are shy to flower when grown outdoors[49, 59]. The flowers have a soft sweet perfume[245].
Cultivation
It needs regular water until established, then extremely drought tolerant, though regular water is fine with them any time. It is very tolerant of bad or salty soil. Shade causes leggy growth and stunts blooming, as does fog.
Prune to control size and shape in the early spring. Old wood should be removed, branches may be cut to ground. Unwanted suckers should be hand pulled, not cut, for best control. Pinching or pruning of grow tips can help keep height down. Cut branches exude a milky sap (poisonous as well!).
Potted plants do not like frequent repotting.
Prefers a heavy soil[49]. Prefers a light soil according to another report[202]. Requires a position in full sun[49, 184]. Prefers a fertile well-drained soil[200]. Lime tolerant[200, 202]. Plants are very tolerant of heat and also of drought once they are established[166]. Grows well in maritime gardens, tolerating salt-laden winds[200]. This species is not very hardy in Britain, though plants tolerate temperatures down to -5°c and short periods of temperatures down to -10°c[184, 200, 260].
Propagation
For exact clones of the parent variety, cuttings are required. In spring or summer, take a 15 cm cutting without flowers and place in water. When roots reach 3 cm, it can be potted up. After it is established it can be planted in the garden. It will grow very quickly under the right conditions, and may flower the same year. Seeds can be planted as well, for new varieties.
Seed - sow spring in a greenhouse[113]. Do not use seed from pods infected with the bacterial disease 'oleander knot'[113]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse for at least their first winter before planting them out in early summer. Cuttings of half-ripe side shoots, August/September in a frame. Good percentage[78]. Cuttings of mature leading shoots[1].
Pests and diseases
- Oleander caterpillars can eat much of the plants leaves.
- Greenflies may appear in warm/dry spring weather, attacking tender buds. They are yellow or ochre and suck the sap from tender buds, weaken them, and make them sticky. Mineral oil with insecticide is effective.
- Cochineals - like scabs that stick to leaves/buds. These also make plant sticky and can be treated with insecticide.
- Oleander leaf scorch, caused by the bacterium Xylella fastidiosa, can cause extensive mortality.
Cultivars
Nerium oleander is the only species in the genus Nerium. The following is a list of selected named cultivars:
- 'Sister Agnes' - single white flowers. Very vigorous, to 6 m.
- 'Mrs. Roeding' - double flowers, salmon/pink, to 2 m, with smaller leaves.
- 'Hawaii' - single salmon/pink.
- 'Petite pink' - easily pruned to 1 m, not as cold hardy as others.
- 'Petite salmon' - easily pruned to 1 m, not as cold hardy as others.
- List of some very hardy varieties, between dwarf and regular size plants in size:
- 'Algiers' - deep red
- 'Casablanca' - white
- 'Ruby Lace' -bright red, 6 cm flowers with wavy edges
- 'Tangier' - soft pink
- 'Marrakesh' - red. 1.5-2 m.
- 'Morocco' - white. 1.5-2 m.
Gallery
Standard Cyclopedia of Horticulture
ExpandRead about Nerium oleander in the Standard Cyclopedia of Horticulture
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ExpandRead about Nerium oleander in the Standard Cyclopedia of Horticulture
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ExpandRead about Nerium oleander in the Standard Cyclopedia of Horticulture
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References
- w:Nerium oleander. Some of the material on this page may be from Wikipedia, under the Creative Commons license.
- Nerium oleander QR Code (Size 50, 100, 200, 500)
- Plants for a Future - some creative commons text incorporated from PFAF.
- Sunset National Garden Book. Sunset Books, Inc., 1997. ISBN 0376038608
External links
- ↑ Sunset Western Garden Book, 1995:606–607
- ↑ Pankhurst, R. (editor). Nerium oleander L. Flora Europaea. Royal Botanic Garden Edinburgh. Retrieved on 2009-07-27.
- ↑ Bingtao Li, Antony J. M. Leeuwenberg, and D. J. Middleton. Nerium oleander L. Flora of China. Harvard University. Retrieved on 2009-07-27.
- ↑ INCHEM (2005). Nerium oleander L. (PIM 366). International Programme on Chemical Safety: INCHEM. Retrieved on 2009-07-27
- ↑ Jump up to: 5.0 5.1 Huxley, A.; Griffiths, M.; Levy, M. (eds.) (1992). The New RHS Dictionary of Gardening. Macmillan. ISBN 0-333-47494-5.