One of the most important things to learn when dealing with a landscape design is to learn to check what the mature heights and sizes of your chosen plant material is.
More often then not, I run into cases such as the above photo. The plants seen there are what I would consider to have been planted in the wrong spot. Yes they may be small and cute looking when you see them on sale at the nursery... but remember this important lesson! Always check the I.D. tag for the plant's specifications.
How big will it get? How tall and wide will it grow? Does it need full sun or part shade? The spot you are thinking to plant it in... does it have the space needed for the mature size of this plant? Will you constantly be pruning it back so it does not block pathways and hide crucial things like a view to your front door?