Complete guide to topiary

Topiary plants are perfect for high-profile spots close to the home that are on view all year round, or by frequently used places like summerhouses, seating areas and pathways. Topiary is a top choice for front gardens and a pair of identical plants flanking a doorway or gate has a timeless appeal. Small topiary balls are a long-lived decorative option for window boxes, while bigger ones can help add winter interest to a border. In patio pots or raised beds, topiary shapes make excellent standalone features or create handsome contrasts to seasonal flowers.

Best plants for topiary

The best plants to use for topiary are small-leaved evergreen shrubs that respond well to trimming and which look good all year round. While Box (Buxus sempervirens) has long been the traditional choice for small topiary, especially balls, its susceptibility to disease and pest problems makes it wise to choose an alternative, particularly in areas of high-rainfall. Japanese holly (Ilex crenata) is a good alternative to box. It looks similar to box and is suitable to trim into small topiary shapes such as balls and cones.

The best larger shrubs, conifers, and trees to use for both simple and complex topiary are small-leaved privet (Ligustrum japonicum) and yew (Taxus baccata). There's also Bay (Laurus nobilis), which has large leaves and is suitable for simple balls and for standards. Cupressus ‘Castlewellan’ is a tall-growing conifer that is trained into spirals.

Another option to create speedy ‘cheat’s topiary’ is to buy wire frames on which to train small-leaved ivy (Hedera helix), by regularly winding in and trimming the stems.

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Growing topiary in pots

Topiary plants work well in pots. Grow in a soil-based potting compost such as John Innes no 3. Stand the pot on gravel or raised just off the ground so excess water drains freely, and water regularly during the growing season. Feed in spring with controlled-release fertilizer. Once the plants’ roots have filled the pot, either pot on into a larger container or top-dress annually, by removing the top few centimetres of compost and replacing with fresh.

To ensure stability with larger, top-heavy topiary plants such as standards and spirals that are liable to fall over, plant your topiary in a good-sized, heavy pot such as one made of wood or terracotta. If using a lightweight pot add a couple of bricks to the base before planting.

Topiary pruning

Any plants that are clipped into shape, from hedges to topiary specimens, need regular trimming every year to maintain a smart, crisp shape. Prune several times during the growing season.

When to prune topiary

Make the first trim of the year when plants are growing strongly, usually around late May or early June – always check for nesting birds before cutting. Then, depending on the weather conditions during summer, make a second cut around July-August. The final cut of the year is best done in early to mid-autumn, but no later, because the new shoots stimulated by pruning need time to ripen before temperatures drop or scorching could occur. This final clipping ensures plants keep a sharp, neat outline for months and look handsome until spring is well under way.

• How to trim topiary

Tools for pruning topiary

Choose tools according to the size of plant. Hand shears are fine for small plants while powered trimmers are easier for large ones. Whatever you use, ensure the blades are sharp to avoid bruising the cut stems, which would then turn an unsightly brown.

Using topiary frames

While small topiary balls and simple shapes are straightforward to train by eye, you can achieve perfect symmetry on larger pieces by using a wire frame placed over the plant. This is a good way to create your own topiary from scratch rather than buying costly ready-grown plants.

Topiary problems

Box is still widely sold as a topiary plant but is prone to box blight disease and box moth. In high-rainfall areas of the country, box blight is particularly virulent, and choosing an alternative to box in these situations is recommended. Both box blight and box moth, whose caterpillars eat box leaves, can cause your box topiary to turn brown. Other reasons for topiary plants turning brown include clipping with blunt pruning tools, which can bruise the leaf rather than making a clean cut, and pruning in very hot, sunny weather.