TOPIARY, as shaped trees and hedging plants are generally known, is definitely the height of style (again).

Back in Roman times owners of large houses included a topiarius on their staff whose function was the maintenance of ornamentally clipped bushes and trees, known as topia. Renaissance Italy saw a massive upsurge of interest in the form which has waxed and waned up to the present day.

Now topiary is viewed as an imaginative and creative way to bring evergreen structure, as well as wit and fun, to the garden.

Box (Buxus), yew (Taxus) and laurel (Laurus) are the main species used in this country for ornamental clipping, but others can respond well too.

These three have the advantage of being evergreen, which gives the effect year-round, as well as being readily available in shaped forms from garden centres and nurseries.

Of the three, yew is the toughest, tolerating acid or alkaline soil conditions, sun or shade, dry conditions and urban pollution. However, all parts of the plant are toxic if eaten.

Box is happy as long as it doesn't have to cope with full sun and dry soil, in which case leaves become dull or scorched. Laurel is only happy down to -5C and is best kept out of cold winds.

In regions with harsher winter conditions, keep laurels in large containers and move them into a greenhouse over winter.

Nurseries have produced some real show pieces recently.

One of the best things about topiary in the garden is that it allows you scope for very clear self-expression - it's completely up to you what you do with it!

The main options for bringing topiary to your garden include formal hedging, geometric shapes or lifelike impressions crafted from the living plants.

Container growing adds to the flexibility of this approach and makes it possible to adorn steps, patios or drives. You can choose between ready-grown specimens, or take the DIY route and teach yourself as you go.

Either way, to maintain a topiary shape you'll need to become proficient with the clippers.

Topiary is a great aspect of gardening to get into and there are some great historic topiary collections to visit.

From Hampton Court Palace in the south to Levens Hall in the north, make a trip to see some wonderful examples of this horticultural art form.