Which plants to choose?
Most plants suitable for topiary are evergreen (to retain their shape year round), have woody stems (which will readily hold the form) and have small leaves and densely compacted foliage (which responds well to tight clipping and shaping).
For this reason, plants such as common box ( Buxus sempervirens), lavender, rosemary and Lonicera nitida have long been popular choices for this art form. Larger trees such as yew (Taxus baccata) with its tight, fine dark green foliage, English holly (Ilex aquifolium) and bay laurel (Laurus nobilis) with its naturally rounded form and glossy evergreen leaves have also been popular – especially for larger topiaries.
Upright conifers such as Thuja also make good candidates for topiary – especially if the desired shape is similar to the plant’s natural form – thin conical forms and flat geometric ‘walls’ for instance.
Many of our own native plants respond equally well to tight clipping, and whereas they may not have quite such fine leaves (to produce intricate detail) as some of their European counterparts, their evergreen nature and tough foliage make them ideal candidates for shaping into simple geometric forms such as cubes, cones and spheres.
Many pittosporum and coprosma cultivars make quite wonderful topiary specimens.
How to clip?
Although there are shaped wire cages available to help the novice create an even geometric form, the more traditional approach to topiary demands a keen eye, a steady hand and a tonne of patience.
Although electric hedge clippers can be used to sculpt larger shrubs, these are best used on plants with very fine foliage – plants with larger leaves should always be carefully cut by hand using secateurs or clippers, taking care not to cut leaves in half but trimming through the stem instead.
When cutting flat-sided geometric forms, a taught string-line may help to keep lines straight and tops level.
Quite complex topiary-like forms can also be created by growing small-leafed ivy (or other fine-leafed evergreen climbers) over a ‘cage’ formed from wire.
As the densely compacted foliage grows around the metal cage it will quickly form a cloak of evergreen foliage and once the cage is completely covered, the plant will need an occasional ‘haircut’ to keep it looking nice and neat.
Topiary standards are another option
– this is where the main upright stem of a plant is trimmed of all side shoots leaving a ‘head’ of stems and foliage at the top.
This is then often trimmed into a geometric shape (usually a sphere in the case of buxus standards) or the plant is left to develop a more relaxed habit (think of ‘Mop Top’ robinias or standard roses).
Topiary standards can be created at home by carefully removing the side branches below a certain height and staking the plant to a cane along the main stem – this will keep the standard upright and help to support the main stem until it thickens.
Plants such as upright rosemary and lavender lend themselves particularly well to this type of topiary project.