Nerium oleander Luteum Plenum

Oleander 'Luteum Plenum' is undeniably one of the most beautiful bushes of the summer. It produces a large number of beautiful, very double, crumpled flowers, sporting a delightful golden yellow colour, grouped into generous clusters with an exquisite fragrance. They bloom as long as the summer lasts providing the soil does not dry out too much. In all respects this is an excellent evergreen bush for a mild climate, very floriferous, easy to grow, and resistant to sea spray as well as drought. Oleander is undemanding in terms of soil type and has amazing adaptability to the most difficult conditions; its only weak point is its relatively poor hardiness, particularly during its early years. Cultivation in open ground is therefore to be reserved for regions that do not experience very cold winters. Installed in a large pot it is the star plant of the summer, to be displayed on the balcony, terrace or patio, or in a small garden, not far from the house.

The numerous cultivars of oleander (Nerium oleander in Latin) available on the horticultural market are most often hybrids between Nerium oleander subsp. oleander, spontaneous around the Mediterranean, and Nerium oleander subsp. indicum, very fragrant, spontaneous from Iran to China. They offer an almost infinite palette of tones, from white to pink, through yellow and salmon, red, and even mauve. Only the blue shade is absent.

Nerium oleander is an evergreen bush from the Apocynaceae family, like periwinkles or false jasmine (Trachelospermum jasminoides). The cultivar 'Luteum Plenum' is naturally dense and bushy, ramified near the base, with a generally rounded habit. It will reach an average of 3 m (10 ft) in height and 2.50 m (8 ft) in spread at maturity, with rapid growth. Its flexible branches, covered with grey bark, carry long evergreen leaves, thick and leathery, of a somewhat ashy green with a 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 made up of a tube flaring into 5 deep red petals, alongside thin and turbinate 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.