A rapidly growing shrub, the evergreen oleander (Nerium oleander) grows 1 to 2 feet per year, according to Clemson University Cooperative Extension. It will reach a height of up to 20 feet and attain a width of around 10 feet, if left to grow naturally.
An oleander killed by a frost or a hard freeze will regrow rapidly from its root system once the old, dead growth is cut away. Damage usually occurs if the temperature dips below 20 degrees Fahrenheit, according to Texas A&M University AgriLife Extension.
Oleanders flower only on new growth. Pruning the shrub in the fall months encourages it to reproduce new stems and bloom profusely. The oleander will flower year round. It produces clusters of blossoms in shades of pink, lavender, salmon, apricot, red, purple, pink and white. Each flower measures approximately 2 inches in width.
Full sunlight encourages the oleander to produce a dense canopy. The shrub will grow in partial or even full shade, but its growth will be seriously stunted and leggy, according to Texas A&M University AgriLife Extension.