In small gardens, the emphasis should be on plants that have much to offer or on compact growth. The hedges suggested here are just some of the plants that could be used to mark your boundary without being dull or oppressive. Be prepared to experiment with others.
Ask yourself if you are really looking to install a hedge. If you are looking to define boundaries rather than create divides, don’t install a hedge. Instead, try establishing tall varieties of heathers.
Choose a hedge that can be clipped for formality. The classic box hedge (Buxus sempervirens) is still one of the best. It clips well and can be kept compact. Choose the variety Suffruticosa if you want a really dwarf hedge like those seen in knot gardens. A quick-growing substitute is Lonicera nitida; there's a golden form that always looks bright but be prepared to cut frequently. Some of the dwarf Berberis can stand close clipping; try the red-leaved Berberis thunbergii 'Atropurpurea Nana'. Yew (Taxus baccata) is also excellent for formal clipping, and it can be kept compact enough for a small garden.
Select colorful foliage for informal hedges. If you want to cut down on clipping and want something brighter and more colorful than most foliage hedges, try the grey-leaved Senecio 'Sunshine' or the golden Philadelphus coronarius 'Aureus.' Unfortunately, the Aureus sheds its leaves in winter, so be prepared for clean up.
Pick a flowering hedge. Many of the flowering and foliage berberis also make good 'shrubby' hedges. These will lack a neatly clipped profile, but pruning and shaping is normally only an annual job. Viburnum tinus can also be kept to a reasonable height and, provided you avoid pruning out the new flowers, it will bloom in winter.
Plant roses to create an informal or formal hedge. Roses make delightful--and often fragrant--boundaries, but they have shortcomings. Their summer beauty is matched by winter ugliness, and they are not a good choice for a boundary where passers-by may be scratched by thorns. You can use a row of floribunda. Many shrub roses can make an attractive flowering hedge in summer, but do not plant them too close to the edge of a path as their thorny stems may be a nuisance.
Choose herbs for a fragrant hedge. Old-fashioned lavender and rosemary dividers are great for defining boundaries and giving off fragrance. Both these herbs make excellent informal flowering hedges with the merit of being evergreen too. Combine them by planting the shorter lavender in front of the taller rosemary. Both become untidy with age, so replace the plants when it becomes necessary.
Consider the upkeep of hedges. Don’t select a hedge that will quickly overtake a small space. Forsythia is one of the most popular flowering hedges, but careful pruning is required to achieve consistent flowering on a compact hedge.