The neriums are evergreen shrubs for the cool greenhouse which grow up to 10 ft. in height and bear terminal clusters of attractive. The foliage is narrow and leathery and reminiscent of willow. The best known species is Nerium oleander, the Oleander or Rose Bay, and another is N. Odorum, both being available in double- and single-flowered forms in colours from white to deep pink. They flower from June to October.
The plants should be potted in tubs or large pots in February or March using John Innes No. 3 Potting Compost or be planted in well-drained beds of loamyin a light sunny greenhouse. The temperature from September to March should be between 7 and 13°C. (45 to 55°F.) with normal cool house temperatures for the rest of the year. The plants do not require shading.
Watering and Feeding
The plants need large quantities of water between March and September but only moderate quantities from then until November and hardly any between November and March. Feeding with liquid fertiliser is advisable once or twice weekly between May and September, and syringe twice daily from March to June. Young shoots which emerge from the base of the flower trusses should be removed as these will rob the flowers of their food and they will wither.
Cuttings can be rooted in spring or summer in a propagating frame with a temperature of around 16°C. (60 F.). Firm young shoots, 3 to 6 in. long, should be chosen for this purpose, these being trimmed and inserted in 2-in. pots filled with a sandy compost. Another method is to root cuttings of mature wood in water during the summer.