Oleander belongs to the Apocynaceae family. The wild species Nerium oleander colonises riverbanks and cool valleys around the Mediterranean, southern Europe and North Africa, and extends into southwestern Asia as far as the foothills of the Himalayas and Myanmar. It is an evergreen shrub adapted to mild winters and hot summers.
The cultivar 'Margarita', often sold under the name 'Margaritha', is an old horticultural selection that shows good cold resistance compared to many classic oleanders. In the ground and in a favourable climate, the plant forms a large, bushy shrub 2.5 to 3 m tall and 2 to 2.5 m wide, sometimes more with age. Its twigs, first green then grey-brown, stand upright then arch slightly under the weight of the flowering. The shrub shows rapid growth after the establishment period. The root system is powerful, deep and well-branched, capable of withstanding periods of drought as well as episodes of temporarily wet soil.
The foliage is evergreen in mild climates: the leathery, narrow and lanceolate leaves measure 10 to 15 cm long. They are a glossy dark green on top, paler underneath, in opposite pairs or in threes around the twigs. From late spring until the first frosts, 'Margarita' bears very dense terminal clusters or cymes. Its single, funnel-shaped flowers measure 4 to 5 cm in diameter with five rounded petals. They open bright pink, lighter on the edges, around a darker throat, often streaked with red. The scent is light. Flowering renews itself continuously if the soil remains slightly moist and faded clusters are removed. The fruits, when allowed to form, are long, brown, cylindrical pods, containing seeds equipped with a tuft of silky hairs; they are not very decorative and are often pruned. Fairly hardy for an oleander, this variety tolerates frosts close to –10 °C in well-drained soil. It produces a very toxic white latex: all parts of the plant are dangerous if ingested, it is prudent to garden with gloves and avoid burning the wood.
Nerium oleander 'Margaritha' can be used in an informal or pruned hedge, in a border or as a solitary specimen near the house, anywhere the sun shines. In southern areas or by the sea, it forms the evergreen base of a Mediterranean-style display. Pair it, for example, with the cultivar 'Alsace', white and very hardy, and with Nerium oleander 'Variegata', with variegated foliage. At its base, you can grow clumps of Agapanthus 'Phantom', purple rockroses and Perovskia 'Blue Spire'.
Cultivated since antiquity, the oleander has accompanied the civilisations of the Mediterranean basin and the Orient; traces of its cultivation are attested in Mesopotamia and ancient Egypt, and it is mentioned by Theophrastus in his History of Plants. Even today, rows of oleanders line the roads and gardens of the South. 'Margarita', with its brilliant pink flowering, is part of this long tradition of an ornamental plant emblematic of holiday landscapes.
