A bit of formality is not out of place in any garden, and precisely pruned cones and spheres of foliage—a classic form of topiary—are especially suited to containers. All that’s required is a beautiful pot, a plant amenable to frequent pruning, and patience.
There are myriad ways to incorporate topiary into your landscape. Try a container with a herb topiary—say, rosemary or bay—as a focal point in a collection of potted herbs near a back door. A large urn with a dramatic topiary of coleus flanking a front door offers an elegant welcome; two identical specimens standing sentry on either side are particularly suitable for a formal, symmetrical facade. A topiary can also be used to add a contemporary look, especially when it’s housed in a sleek metal planter or minimalistic concrete pot.
Generally, the size of the container should be similar in size to the mature head of the topiary’s foliage. Whatever the material or style, the container must have a drainage hole. If it doesn’t, use it as a cachepot and place the plant in a plastic grow pot that fits inside. Empty the cachepot after watering.
Choose a specimen with a straight central leader (it’s fine to start with a young plant; transplant it into incrementally larger pots as it grows). Carefully insert a slim bamboo stake into the soil alongside the central leader—the top of the stake should reach the bottom of the (ultimate) head of foliage. Using soft twine, secure the stem to the stake with a figure-eight tie.
Clip off all side branches from the base of the plant to where you want the bottom of the head of foliage to grow. To promote new branches at the top, prune off a centimeter or two from the tip of the central leader. If you’re starting with a small plant without a lot of foliage, don’t clip off all the side branches at once; do this in stages over a few weeks, as pruning too much foliage at once stresses a young plant.
Now that you have the rough framework of your topiary, wait for new growth at the top before starting to shape the crown. When pruning, step back periodically and look at the plant from all angles. As with bad haircuts, a lopsided topiary will eventually grow in, but it requires time.
To keep a dense symmetrical shape and trigger denser branching, prune lightly but frequently during the growing season. Don’t let it get unruly—it’s better to take off a centimeter or so rather than several centimeters at a time. Plants with large leaves, such as bay, sage, and scented geranium, should be cut back to a leaf node. Those with small leaves, such as rosemary and lavender, can be lightly sheared.
Fertilize during active growth—in spring and summer—every two weeks at half the recommended strength with a balanced fertilizer such as 10-10-10. Herbs need less frequent feeding; about every six weeks is fine.
Mulch—use objects such as terracotta beads, small shells, polished pebbles or gravel—retains moisture and adds an attractive finishing touch, but keep it away from the stem of the plant. Rotate pots every few days to encourage uniform growth.
Small-leafed shrubby plants make the best candidates for topiary. All the examples listed here, except for the boxwood, sage, and lavender, can be overwintered indoors in a sunny window in Zones 5 and lower. Boxwood, lavender, and sage may be overwintered outdoors in Zones 6 and higher in large, double-walled containers in a spot sheltered from the wind and direct sun.
- Boxwood (Buxus spp. and CVS.)
- Sweet bay (Laurus nobilis)
- Lavender (Lavendula spp. and CVS.)
- Greek myrtle (Myrtus communis)
- Scented geranium (Pelargonium hybrids)
- Rosemary (Rosmarinus Officinalis)
- Sage (Salvia officinalis)
- Santolina (Santolina chamaecyparissus)
- Coleus (Solenostemon CVS.)
- Germander (Teucrium fruticans)