@ctrl-alt-nwo, That's very beautiful leaves & flowers indeed plant introduction. I add some via web site.
Most oleander cultivars reach a height of 8 to 12 feet and spread to cover an area of about 10 feet when fully grown. Each year, a plant generally adds 1 to 2 feet to its height, although dwarf cultivars add proportionally less, depending on their mature size.
Native to the Mediterranean region and parts of Southeast Asia, oleanders are evergreen shrubs with leathery, sword-shaped leaves and showy flowers that appear during summer in many colors, depending on the cultivar. Giving an oleander some basic care can ensure it grows at a steady rate and eventually reaches its mature size.
An oleander grows best in a spot that gets bright sun for most of the day, although it can tolerate partial shade for a few hours each day. In areas with hot, intense summer sun, the best location is one that gets full sun until early afternoon and then gets light, filtered shade during the hottest afternoon hours. An oleander plant can be damaged by cold spells, doing poorly if the temperature falls below freezing for an extended time.
Although an established oleander requires little or no fertilizing, feeding a young plant can maximize its growth rate and help it mature quickly. Feeding is best done in early spring, when new growth first appears, and again in early fall, to help the plant store nutrients for the next season.
Source: http://homeguides.sfgate.com/growth-rate-oleander-plants-75907.html