Growth rate
The growth rate listed is an approximation of the speed of growth and time taken for the plant to reach its full size.
The indication of whether the growth rate is fast, moderate or slow is based upon the time taken to reach its full height and what that full height is. Therefore a plant which grows to its full height of 1 metre in 10 years may be considered slow, whereas a plant growing to 10 metres in the same time period may be considered fast.
Even taking into account the different rates of growth for different sized plants, there are many more variables which can affect the growth rate, such as the soil type, rainfall, nutrition and exposure. So the growth rates shown should only be taken as a rough guide and nothing more!