To say that trees are the slowest-growing of all plants is misleading. Just because a tree might take a century, or even more, to reach its ultimate height does not mean that it is slow, just big! But woody plants do vary enormously in the speed at which they grow and the slowest can frustrate your efforts to achieve early maturity. This does not mean that the fastest are necessarily the best to choose. Rapid shrubs can be coarse and leggy, or can be immature even though they get large quickly. These may be useful for a quick-growing shelter belt on the edge of the property. For the central part of design, there is more to making the best selection than going for the fastest growers. We need artistic merit as well as speed.
Nigel Colborn, 'Shortcuts To Great Gardens'