One of the elements of garden design that designers use is that of structure. While perennials and annuals come and go within a garden accenting it, it is the more permanent aspects of a garden - manmade like arbours or pergolas, or plants like shrubs and trees - that gives it structure, adding strength and often character to a space.

Trees are brilliant structural plants. When our horizontal opportunities are limiting trees allow us to capitalize upon the vertical possibilities often making the space feel bigger. They also add definition to a space too; for instance a single tree planted in the centre of an island bed defines a space in one way but a line of trees along a pathway adds a different dimension cmpletely. The age of a tree can also add a sense of history or context to a garden while the tree itself brings layers of biodiversity to a garden through the different species it supports. All in all a tree's reassuring presence throughout the seasons makes it a first port of call for any garden designer looking to add structure to a garden.

Our top 3 trees for adding structure to a small garden are:

Amelanchier - (Image above) A beautiful group of trees with a great shape. As the wind blows through it you often get a silvery sheen to it which gives it an ever changing look. Its spring blossom is fabulous and its autumnal colour spectacular.

Sorbus - (image left) all varieties are lovely delivering beautiful spring blossom , striking autumn berries and leaf colours in differing combinations. For instance Sorbus aucuparia 'Joseph Rock' has white flowers in spring with creamy yellow berries in autumn along with orange, purple and red leaves. Sorbus commixta 'Embley' has scarlet autumn foliage, orange berries and white blossom in spring.

Prunus - the Prunus serrula 'Tibetica' - with its distinctive peeling bark that looks good all year round, especially in the cold, frosty winter light. It also has pink spring blossom and great autumn leaf colour.

All of these great trees earn their keep in any garden - they're all deciduous and none of them grow too large - but for a small garden in need of good structure you'd be hard pushed to find any better alternatives .