Nerium oleander

Nerium oleander subsp. var.	Oleander
	Habit: shrub Height: ⇕ to Width: ⇔ to 2m6m 2m5m Height: ⇕ 2 m to 6 m Width: ⇔ 2 m to 5 m Lifespan: ⌛ perennial Origin: ✈ Medit. to China Poisonous: ☠ highly toxic, fatal Bloom: ❀ mid spring, mid summer, mid fall	Exposure: ☼ sun Water: ◍ moist, moderate, dry Features: ✓ flowers, drought tolerant Hidden fields, interally pass variables to right place Minimum Temp: ☃ -10°C263.15 K 14 °F 473.67 °R USDA Zones: 9 to 11 Sunset Zones: 8-16, 18-31 Flower features: ❀
	Apocynaceae > Nerium oleander var. ,

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/), 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.

Oleander shrub, Morocco

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. 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.

Flower Bud of a White-flowered Cultivar

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. 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

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  Oleander shrub, Morocco

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  Flower bud of a white-flowered cultivar

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  Buds of Nerium oleander. From Lisboa, Portugal

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Standard Cyclopedia of Horticulture

Standard Cyclopedia of Horticulture

Nerium (ancient name for oleander, supposed to be from Greek neros, "moist," alluding to the places in which it grows wild). Apocynaceae. The oleander is an old-fashioned evergreen shrub known to everybody, and cultivated everywhere in southern countries. In the North the oleander is a common house plant, being grown in tubs for summer decoration, and ranking in popularity with sweet bay and hydrangea. Oleanders are erect glabrous shrubs: Lvs. in whorls of 3, rarely 4 or 2, narrow, leathery, transversely feather- veined: fls. showy, rose-red, white or yellowish, in terminal cymes; calyx with many glands inside at the base; corolla-tube cylindrical at the base; throat bell- shaped and containing 5 wide or narrow teeth; lobes twisted to the right; anthers 2-tailed at the base and tapering at the apex into a long thread-like appendage; style 1; ovaries 2, forming pods; seeds twisted.—Species probably 3, with varieties. Medit. region to Japan. The common species, so very widely cultivated, is N. Oleander. It attains 7 to 15 feet, and blooms in summer, the flowers being salver-shaped, five-lobed when single, 1½ to 3 inches across, and commonly pink or white, though the colors range from white through creamy white, blush, rose and copper-color, to crimson and dark purple, with variegated forms. It is of easy culture, and is well adapted to city conditions. The chief troubles are scale and mealy-bug. The scale should be sponged off; the mealy-bug is easily dislodged by the hose. Sometimes a plant forms buds which open poorly or not at all. This is often due to the imperfect ripening of the wood. The flowers are borne on the growth of the year, which should be well ripened in June in order to set many strong buds. For this purpose give the plants plenty of light and air, and water more sparingly when the vegetative growth seems to be finished. After flowering, give the plants less water. Protect them from frost in winter; keep them, if necessary, in a light shed. In April, prune back the old wood which has borne flowers and give more warmth and water. The ripened leading shoots can be rooted in a bottle of water. Oleanders are poisonous, and some persons have died from carelessly eating the flowers. Cattle have been killed by eating the foliage. It is said that in California the oleander is immune from the depredations of the gopher.—Oleanders in the East (H. A. Siebrecht): The following method of oleander culture has been pursued by the writer with success. Propagation is performed after the flowering period. Good- sized cuttings are taken, and every one grows. When rooted, the cuttings are potted in small pots and kept barely alive over the winter. They will need scarcely more attention than geraniums until February or March, or whenever growth becomes more active. Later in the spring, the young oleanders are planted outdoors in the open ground, in good rich loam or garden soil. (This is sometimes done with ivies or evonymus, but the common method is to plunge the pots outdoors during summer.) Take up the oleanders in September, pot them and bring them indoors for their second winter. The following spring the plants will bloom; but they will not be shapely. The time has now arrived to train them, either as bush plants or crown standards. Top them at whatever height is desired, say 2 or 3 feet, and the plants will make good crowns the same season (i.e., their second summer). Do not allow the plant to bloom the following spring (which is its third spring), and the result will be a fine specimen in full flower for the fourth summer.—Oleanders in California (Ernest Braunton): Oleanders are much grown in southern California, and would be extremely popular were it not for black and other scales, which seem to prefer them to everything else. We have five colors here, perhaps all of the same species—white, light pink, dark pink, scarlet and buff. Most of these colors, if not all, can be had in both single and double forms. The writer has never seen an oleander more than 20 feet high, but he thinks they will grow larger. One Los Angeles man planted the red variety twenty-seven years ago for sidewalk trees. (For this purpose, if cleaned of scale when necessary, the oleander is one of the very best.) The trees are heavily pruned and topped every third year. They are now 12 feet high and 6 to 8 inches in diameter at base. Oleanders need no attention here, and are as readily propagated from hardwood cuttings as willow. They are very floriferous, and the inflorescence comes out in large heavy heads, necessitating a close pruning to make them self-supporting. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

Standard Cyclopedia of Horticulture

Nerium odorum, Soland. Sweet-scented Oleander. Stout erect shrub: Lvs. in 3's, linear-lanceolate: fls. rosy pink, 2 in. across, in clusters of as many as 80, fragrant; appendages of the anthers protruding; segms. of the crown 4-7, long and narrow. Persia, India, Japan. B.R. 74 (fls. double). B.M. 1799 and 2032. G.C. III. 50: suppl. July 8, 1911.—A less robust plant with Lvs. commonly narrower and more distant, and angled branches. In wild plants the calyx-lobes of N. Oleander are spreading; of N. odorum erect. It has the same range of color as the above, and single and double forms. Prop, by layers or cuttings. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

Standard Cyclopedia of Horticulture

Nerium oleander, Linn. (N. lauriforme, Lam.). Oleander. Rose Bay. (Another plant called "Rose Bay" is Epilobium angustifolium.) Fig. 2476. Lvs. in 2's or 3's, lanceolate: appendages of the anthers scarcely protruding; segms. of the crown 3—4-toothed. Medit. region, Orient. Gn. 51, p. 81 (fine trees in vases). A.F. 10:265 (Bermuda shrub with a spread of 25 ft.). L.B.C. 7:666 (var. Loddigesii, with a variegated fl. and the appendages entire, ovate and obtuse). N. album, N. atropurpureum, N. carneum and N. roseum, Hort., are doubtless varieties. The plant is common in subtropical and tropical countries, sometimes planted in hedges, and sometimes runs wild. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

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