Topiary or not topiary?: Few people make the effort to shape their hedges into peacocks, ships or rabbits anymore

It's time for the circle of Irish yews we planted on the bank a couple of years ago to turn into people. The 11 trees have grown well and we've kept them slim by tying in the growth at regular intervals with nylon fishing line. Each yew is now about seven feet tall. We could just clip their tops and sides and keep them as separate columns, but from the beginning, I imagined them clasping each other in a circle, like Greek men dancing. The yews now need persuading to grow arms and heads.

The top growth is still young and flexible, and I think the best way to train the topiary will be to drive in stakes behind each tree so that the tops of the stakes are at neck level (the yew people will be a little bigger than life size). Then we can cut willow stems – there's plenty of that about – and tie those horizontally to join the tops of the stakes. Willow is whippy and should bend to make a circle. If we used stakes to make the top support, we'd end up with angles like a dodecahedron.

A handful of the top growth needs to be tied down to the support on the left of each tree, another handful on the right. The bit in the middle for the moment can continue to grow straight up, until it is bulky enough to make the head. For a while the structure will look weird. But I reckon in three years the green fingers of the yew trees will be touching each other in the circle. The heads may take longer.

Topiary is a particularly molten form of sculpture and you have to work with what you've got. The yews may not want to dance. But I'm remembering the monumental piece of topiary in a Lincolnshire place we once rented. The date of the fancifully Gothic house (1846) made me sure that inside the 25ft-high lump of yew we inherited was a peacock screaming to get out.

I charged up the A1 to Clipsham where there is a superb collection of topiaried yew trees, maintained by the Forestry Commission, and got Eric Wyer, chief clipper, to look at our specimen. He reckoned five years to restore it completely, but it was looking brilliant after only three. The chief difficulty lay in physically getting Mr Wyer to the right height to cope with the trimming. The Forestry Commission uses mechanical hoists and the first year, we hired one of those for the job. The expense was crippling. The following years we hired portable scaffolding towers, which were ideal. When the bird was fully back in shape, we could clip it from a ladder. The underpinning was tough and tight and all the bird needed was a once-a-year trim to shear off the previous year's growth. That's a job to do any time between August and Christmas.

That was the most satisfying, most pleasurable piece of topiary I've ever lived with. The bird on its spiralling base was superb, especially in winter, when it gazed in at the bedroom window, green in a landscape that was sear and bare. But the next tenant abandoned the bird. Now, 10 years later, there is no sign that it ever existed. Sacrilege.

Topiary is scarcely ever out of fashion. Mostly it's geometric stuff: spirals, cones, balls, cubes, columns. In town gardens, it looks superb, particularly in winter when the frippery of flowers has gone. But who is making peacocks, battleships, rabbits and teapots now, to delight gardeners in 100 years time? We garden selfishly now: instant gratification and to hell with the future. Driving up and down England, my routes used to be marked by the pieces of topiary I looked forward to: a cat and a dog running along a council house hedge in Raglan (now replaced with a line of Leyland cypress), wedding cake stands either side of a gate at a cottage in Herefordshire, supplanted now by a breeze-block wall. Maintaining a piece of topiary is simple, compared with the art and labour of creating it. But even these great, inherited pieces, the folk art of cottage gardens, are being cut down. I can't bear it.

The bulk of the lollipop bays, the clipped cones and balls of box and yew that you find in garden centres (or in the Columbia Road market in London) are imported from Belgium or Italy. Buying a ready-trained bush of box or yew is undoubtedly the easiest way to introduce topiary into a garden. If you think of the price in relation to a sculpture, it is not expensive. Box and yew are the classic subjects for topiary, because the growth is tight and only needs clipping once a year. If you want to make your mistakes less expensively, try privet for a maquette. Privet is quick and gives quite good results. But its leaves are much bigger than those of box or yew, so the final result is coarser. Shapes need to be kept simple and clipped frequently.

Barnaby Googe, writing in the Four Books of Husbandry in 1577, particularly mentions rosemary as a good subject for topiary, though the stems are lax when young and it never makes a large specimen. Many rosemaries are sprawlers, so you need to use a naturally upright variety such as 'Miss Jessopp's Upright' and clip twice a year: once after flowering in early summer, and once in late summer. In our new garden, I hoped to furnish the front of a steep bank with rosemary, clipped into globes, as French gardeners use santolina. But even the upright types tend to splay apart from the centre. I may have to let them sprawl, as they so obviously want to do.

Rosemary needs sun. Yew, box and bay will all survive in shade and in thin soil, which is another reason they do so well in town gardens. Bay lollipops are great favourites in tubs either side of a doorway. They are not difficult to train. Buy a straight-stemmed young plant, fasten the stem to a cane and as the tree grows, pinch out the side shoots gradually to leave the lower part of the stem bare. When the trunk is as tall as you want, pinch back the shoots at the head to make them bushy.

Established specimens can be kept in pots indefinitely. They become difficult to repot, but you should at least scrape away the top few inches of compost each year and replace it with a fresh mix. You also need to water and feed the plants regularly. I use Osmocote slow-release granules. Scattered on the pots in spring, they last the entire season. If the evergreen foliage gets dusty in summer, spray it with a hosepipe.

Topiary specimens to plant from early November onwards are available from Langley Boxwood Nursery Ltd, Langley Lane, Rake, Nr Liss, Hants GU33 7JN, 01730 894467, boxwood.co.uk. The Romantic Garden, Swannington, Norwich, Norfolk NR9 5NW, 01603 261488, romantic-garden-nursery.co.uk. Hopes Grove Nurseries sell box balls from 30-40cm (£28) to 60-70cm (£129) and cones from 50-60cm (£25) to 100-120cm (£109). Find them at Smallhythe Rd, Tenterden, Kent TN30 7LT, 01580 765600, hopesgrovenurseries.co.uk