Fresh From the Smithsonian Gardens: a Topiary Toolkit

As living sculptures, topiaries are the art of patiently training leafy plants to take on fanciful forms, like geometrical shapes and animals. Some 2,000 years ago this style of gardening first became popular in Ancient Rome, where topiaries were regarded as a sign a of wealth. In more recent history, topiaries regained prominence during the Victorian Era, when highly ornate touches and fine detailing again became the decorative norm. Today, garden enthusiasts can visit Colonial Williamsburg to see the United States’ oldest topiary gardens that stem back to the 1690s, and increasingly, even the most modern roof-scapes from Brooklyn to Silver Lake are embracing the “return of topiary” as a latent trend in green design.

If you’re considering trying your hand at topiaries, there are some essential items you’ll want to know about before making your first trim. Garden Collage recently spoke with Cynthia Brown, the Education and Collections Manager of Smithsonian Gardens, to learn more about proper topiary care. As a trained horticulturist, Cynthia’s tool tips can help keep your topiary in tip-top shape. Still, it’s important to remember that topiaries can take years to fill in– but if you plan according to our toolkit below, you’ll be way ahead of the (neatly-trimmed) curve.

The Right Plant

When you choose your plant, it’s a good idea to know how big you want the topiary to be when it matures. Small, tight leaves are generally the simplest to work with when you’re starting out. Evergreen trees and shrubs are relatively easy to shape, so consider using boxwood, holly, juniper, bay laurel, or rosemary. Finding plants that are already slightly shaped like you want them to be eventually is wise as well. So, for a spherical shape, boxwood is ideal given that it’s naturally rounded. You might also want to get a shade-tolerant plant, since certain topiary shapes could block part of the plant from receiving light. We love the selection of topiary available from specialty plant connoisseurs like Snug Harbor in Kennebunk, Maine. (They ship select products, so it’s worth checking out what they have in their beautiful greenhouse…)

Topiary Frames

Unless you’re already a topiary master, frames are a beginner’s friend: freehand trimming a symmetrical shape is much harder than it looks. With a frame, all you have to do is cut off any part of the plant that grows outside of it (GC Tip: Bosmere makes beautiful circular frames that are easy to ship). Topiary frames come in all sizes and shapes, including spheres, spirals, hearts, horses, and birds. Tying your plant to the frame with twine can help train it to fill the space too. If your topiary gets a lot of direct sunlight or you live somewhere hot, it’s wise to use a wood frame like bamboo, since hot metal can damage the plant.

Long Shears

Trimming helps the topiary take shape and promotes fuller growth, which allows the frame to fill in. For larger topiaries, long shears help with cutting tough-to-reach branches. Longer shears are good for “heading in”, the technique for trimming and shaping the outside of the plant. As a rule of thumb, you should never cut more than a third of a plant’s leaves at a time, since that can lead to overstressing. Think of a topiary as a slow motion sculpture–there’s no need to get overzealous with the pruning. The “Three D’s” remind you to trim when a plant is Dead, Diseased, or Damaged. Most young shrubs need about a year to grow and fill in before you can start trimming them.

Short Shears

Commonly known as secateurs, these small, spring-loaded pruning shears allow for one-handed cuts in tight spaces. Short shears are good at the second important type of cutting, known as “thinning” or “pluck pruning”. If you only cut the outside of the plant to shape it, you’ll end up with just a shell. Thinning out the inside of the plant–pluck pruning–promotes growth and allows for air circulation, similar to when someone with thick hair gets it thinned out. Generally speaking, people in temperate climates should prune mostly in the summer and stop just before autumn. That way, the plant’s young, vulnerable leaves don’t just freeze and die when it turns cold.  (Those looking to invest in short shears should try these shears from Amazon– they’re Garden Collage approved!)

Cynthia Brown, our consultant on this piece, runs Community of Gardens, an online digital archive that’s designed to preserve the U.S.’s rich garden history.