Hedges can be used as a formal element when pruned back hard to show strong clean lines in the garden, or as a semi-formal element when allowed to grow to their natural shape and pruned lightly after flowering. Hedges can also be used as dividers in the garden to differentiate one landscape (or room) from another. The most common use of hedging is probably to ensure that relations with neighbours are kept at an even keel (good fences make good neighbours).
The hedging list provided differentiates between small garden hedges (generally in sizes less than 1 m), large garden hedges (which may range from 1 m to 10 m in the case of a leylandi hedge), and barrier or security plants. Pyracantha with its large thorns and dense growing pattern makes for a secure hedge for anyone not prepared to either spend hours with a pruner or sacrifice significant amounts of flesh.
Creepers can also be used as a screen when space is an issue. Creepers are generally grown on a trellis, or attached to a garden wall using nails or wire support. An important decision when choosing a creeper is whether it prefers sun or shade, and whether it is frost hardy or not (see list for details).