What topiary involves
Topiary means clipping evergreen shrubs into balls, cones, cloud shapes, spirals or architectural forms. It's different from hedge trimming in that the shape is the point: a good result comes from a clear outline, level surfaces and regular, light cutting that keeps the dense surface growth.
Plants used
- Yew takes hard cutting, regrows from old wood and suits large, long-lived pieces.
- Box has tiny leaves and a fine finish, but is prone to box blight and box tree caterpillar (see below).
- Privet grows quickly and is easy to shape, but needs clipping more often.
- Bay is often grown as clipped standards and balls, and suits smaller formal pieces.
Box blight and box tree caterpillar
If your topiary is box, two problems are worth knowing. The RHS describes box blight as a fungal disease causing brown leaves, leaf drop, bare patches and black streaks on young stems. Its guidance on clipping includes keeping plants open to air, cutting in dry weather because the fungus spreads in humid conditions, cleaning tools between areas and gardens, and bagging infected material rather than composting it.
The box tree caterpillar is a different problem. The RHS says it can strip a plant completely, leaves webbing between leaves, and is most active from April to October, although caterpillars overwinter in webbed leaves and can feed on warm days as early as February. Control starts with frequent checking and removing caterpillars by hand. Where infestations recur, the RHS suggests considering alternatives to box.
A tree surgeon or gardener experienced with box should be able to tell the two apart and should clean tools between jobs. Ask whether they do this.
Timing of clipping
Timing depends on the plant, the weather and how fast the topiary grows. Slow growers such as yew need fewer cuts than fast-growing plants such as privet. Clip box in dry weather, as the RHS advises, and avoid cutting during the bird nesting season without checking first. Your chosen firm should give you a visit pattern for each plant rather than one date for everything.
Large topiary needs access equipment
Large or tall topiary can't always be reached safely from a ladder. Firms may use a mobile platform or a tracked lift for work at height. HSE guidance on mobile elevating work platforms says they can give a secure working platform, and our difficult access guide explains the main options and why they add to the cost.
Nesting birds
Dense evergreen topiary is attractive to nesting birds. It is an offence to damage a wild bird's nest while it is in use or being built, see GOV.UK guidance on wild birds. Nesting is mostly March to August but can run longer. A good firm checks before each cut and may leave a piece until the young have fledged.
What to ask a firm
- Is this a one-off reshape or a regular programme, and how many visits a year do they suggest?
- How do they clean tools between plants, especially if box is involved?
- Will they check for nests before each visit in spring and summer?
- Who supplies and operates any access equipment, and is it covered by their insurance?
What affects cost
- Size and number of pieces, and the complexity of the shape.
- Whether this is a first reshaping of overgrown plants or routine maintenance.
- Access equipment and the ground conditions beneath it.
- Whether clippings are taken away. Clippings from diseased box should be bagged, not left.
If topiary is in a conservation area or the plant has a Preservation Order, see our TPO and conservation area guide before major cutting.