Topiary is defined as: ‘the horticultural practice of training live perennial plants by clipping the foliage and twigs of trees, shrubs and subshrubs to develop and maintain clearly defined shapes.’ This means that your neatly clipped rectangular cuboid hedge of Beech, Box, Privet, Yew, Hornbeam, Lavender or Leylandii is as much a work of topiary as that 3m peacock in your neighbour’s garden.
For the experienced and ambitious topiarist aiming for elaborate geometric or naturalistic shapes, the classic choice has to be Yew or Hornbeam – though anything you can do with these, you can achieve with Privet.
For true novices, Privet, Box or Lonicera Nitida (Box Honeysuckle) are sensible choices – they’re faster growing and less expensive. I shouldn’t really say this, but losing one of these to the injudicious clipping of an untrained hand is acceptable while Yew and Hornbeam surely deserve safer hands.
And if you want to test yourself on the easiest of topiary’s nursery slopes, then start with Box Balls and/or Box Pyramids. Keeping them in shape over a season or two should give you the experience and confidence to move on to more ambitious projects.
And once you have acquired your plants, there are many free-access topiary training videos on the Internet.