Yes, and the pot does most of the deciding. The Royal Horticultural Society sets two demands for container topiary care. The first is a pot big enough for the specimen. The second is weight, so the plant will not fall over in high winds or once the compost has dried out. Topiary in pots gives you a clipped shape you can stand exactly where you want it, and that is the whole appeal. The shape works as a focal point or an accent, so where you put it matters as much as how you clip it.
The Japanese holly cone by my back door scrapes the brick wall whenever the wind swings round from the west. One November it went further than a scrape. The compost had gone light and dry, the plastic pot tipped, and the cone came down on the path with its tip snapped flat. It stands in a heavy glazed pot now. It has not budged since.
Two simple things sit behind that advice. A container holds a fixed amount of water and nothing more, so the compost in it can dry out, and dry compost weighs very little. Then there is the shape itself. A clipped head sits high and wide on a bare stem, which turns the whole plant into a sail, and a light pot under a heavy head is the pairing that goes over. Neither problem comes from the plant. Both come from what you stood it in.
- Size: Match the pot to the plant you have now, not to the small one you bought three years ago.
- Weight: Use a pot heavy enough to hold the plant upright in high winds and through a dry spell.
- Spring: Mulch with organic matter once a year to keep growth strong and healthy.
- Summer: Trim with topiary shears or hedge-cutters in early or late summer, twice or more if the plant grows fast.
- Look at the shape from the spot people will stand in, since an accent plant only works from the angle it is seen.
Box, yew, holly and privet all take clipping and all show up as topiary subjects. Box carries the most trouble at the moment. Box blight, box tree caterpillar and box suckers all go for it, and any one of them can wreck a shape you spent years building. Root rot from Phytophthora is on the same list. Yew takes the worst of that one, which is worth knowing before you buy a yew ball in a tub. Holly and privet hand you the same clipped outline without the box pest list hanging over them.
Feeding a potted topiary asks less of you than most people expect. An annual mulch of organic matter in spring is the routine, and it is there to keep growth strong. Do that once a year and leave the plant to get on with it. The bigger call is the pot itself, because a container that suits a small ball will not suit the same ball five years on, and moving up a size is easier than propping a fallen cone.
Trim once a year with topiary shears or hedge-cutters, in early or late summer. Fast growers will want a second cut, sometimes more, to hold a crisp edge through the season. Stand the finished plant where its outline reads against something plain, like a door, a wall or the turn of a path. A cone against a busy border disappears. The same cone against brick is the thing everyone looks at, and a pot you can walk right round turns it into a conversation piece rather than background.
Read the full article: Topiary: How to Shape Plants Without Killing Them
