Nerium oleander Sister Agnes

Oleander 'Sister Agnes' is a descendant of Nerium oleander, a vigorous evergreen bush iconic of Mediterranean gardens. This variety, particularly floriferous and fragrant, has single flowers with pure white petals and a cream white throat, in bloom continuously from June to October if the soil remains moist. They are grouped in generous bouquets, highlighted by an elegant dark green foliage, attractive even outside the flowering period. Undemanding, easy to grow in any well-drained soil, resistant to sea spray as well as drought; its only weak point is its rather poor hardiness, especially during its younger years. Cultivation in open ground is therefore reserved for regions that do not experience harsh winters. It can be used in the composition of large, elegant and multicoloured hedges in association with other varieties, and impresses throughout the season in a large pot on the terrace, balcony, or in a small garden.

The numerous oleander cultivars available on the horticultural market are most often hybrids between the Nerium oleander subsp. oleander, spontaneous around the Mediterranean, and the Nerium oleander subsp. indicum, very fragrant, spontaneous from Iran to China. Their flowers are single, double or even triple and offer a nearly infinite palette of shades, from white to pink through yellow and salmon, red, and even mauve. Only the blue shade is absent.

Nerium oleander is an evergreen bush of the Apocynaceae family, like periwinkles or false jasmine (Trachelospermum jasminoides). 'Sister Agnes' is naturally dense and bushy, ramified near the base, multi-stemmed, with a generally rounded habit. Vigorous, it will reach an average height of 3m50 (12 ft) by 3m (10 ft) spread at maturity, with rapid growth. Its flexible branches, covered with grey bark, bear long evergreen leaves, thick and leathery, with a slightly bluish green on their lighter underside. They measure 10 to 15cm (4 to 6 in) in length by 3cm (1.2 in) in width. In the case of intense drought Nerium loses some of its oldest leaves, those located towards the base of the stems. Flowering occurs in spring and then again from late summer to autumn, or continuously over 4 to 5 months from spring to autumn in the right climate, in moist soil. The flowers are composed of a tube flaring into 5 pure white petals with a cream white throat, alongside thin and turbinate very pale and creamy white-yellow buds. They are gathered in corymbs, mainly at the terminal part of branches aged 1 or 2 years. This flowering, nectar-rich and melliferous, is followed by the formation of long reddish pods that burst when ripe, releasing a multitude of small seeds with a tuft of white bristles, to be dispersed by the wind. Be careful not to prune oleander too severely: only stems that have reached a certain length bear flowers!

A symbol of resistance and generosity, Nerium oleander makes an excellent hedge plant by the sea but also a magnificent standalone specimen in a sunny site. Hardy down to -8/-10°C (17.6/14 °F) once well established, it will grow without problem in any ordinary but well-drained soil. It can be used as a hedge plant, with regular pruning, in combination with other evergreen bushes such as Laurustinus, Elaeagnus ebbingei, Mexican Orange, myrtles, Pittosporum tobira and Grevillea. In a mild climate it can be trained as a small tree, by selecting the best stem and bringing it up to 1m50 to 2m (5 to 7 ft) from the ground before letting it branch out. Such specimens are particularly ornamental but require very mild winters that won't risk needing to cut it back to the ground: you don't want to see several years of work destroyed by severe frost in a few hours! It will reign supreme on the terrace in a large pot, in the company of citrus trees, Grevillea and oleanders. This allows the tree to be stored in a very bright, cool but frost-free room over winter in very cold regions.

The genus name 'Nerium' may come from the ancient Greek name Nerion, derived from Nereus, a sea god of Greek mythology. Another interpretation relates Nerium to neros, which means "wet" in Greek. The liquid element common to both interpretations is probably explained by the fact that wild oleander never grows very far from water. Its long roots anchor deeply in the soil to draw up moisture, even on the sides of gorges or the beds of dried-up rivers. As proof of its incredible resistance to drought, in arid regions like the Negev in Israel or the south of the Moroccan Anti-Atlas, Nerium oleander is one of the only bushes (along with Acacia and Retama, a kind of broom) capable of surviving in the desert, anchored in the walls of ravines.