Boxwood is the best evergreen there is for a large container: it holds a shape, it keeps its colour in January, deer leave it alone, and it will live in the same planter for a decade if the planter is right. Most of the potted boxwood that dies, dies of one of three things, and none of them is cold.
The planter is one we carry, photographed by the maker and restaged. The topiary in it is a visualisation: the planter is sold on its own.
Can boxwood grow in a pot?
Yes, and it is one of the few evergreens that genuinely prefers the arrangement. Boxwood roots are fine and shallow, closer to a mat than a taproot, so a wide container suits the plant better than a deep one. What boxwood will not tolerate is sitting in water, drying out completely, or being asked to grow at the rate a fast cultivar wants to grow inside a pot that cannot hold it.
The difference between a container boxwood that looks better every year and one that quietly goes brown from the inside is almost always a decision made before planting: which cultivar, and how big a planter.
Which boxwood suits a container
The number that matters is the growth rate, because a container is a fixed volume and the plant is not. These figures come from the cultivar records we keep on our own growing, and they are the honest basis for choosing.
| Cultivar | Growth rate | Size at 15 years | In a container |
|---|---|---|---|
| ‘Green Pillow’ | Very slow, 0.5 to 1 in a year | 1 ft x 1 ft | Ideal. Decades in the same planter. |
| ‘Morris Dwarf’ | Very slow, 0.5 to 1 in a year | 1 ft x 1.25 ft | Ideal. Decades in the same planter. |
| ‘Green Beauty’ (we grow it) | Slow to medium, 1 to 2 in a year | 2.25 ft x 2 ft | Very good, and it holds colour in heat. |
| ‘Grace Hendrick Phillips’ | Slow, 0.75 to 1.5 in a year | 1 ft x 2 ft | Very good. Spreads rather than climbs. |
| ‘Vardar Valley’ | Slow to medium, 1 to 3 in a year | 1.5 ft x 3 ft | Good, and the hardiest on this list. |
| ‘Green Velvet’ | Medium, 2 to 3 in a year | 2 ft x 2.5 ft | Good. Expect to re-pot eventually. |
| ‘Green Gem’ | Medium, 2 to 3 in a year | 2 ft x 2.5 ft | Good. Expect to re-pot eventually. |
| ‘Rotundifolia’ (we grow it) | Fast to medium, 3 to 6 in a year | 5 ft x 4 ft | Outgrows a container quickly. |
| ‘Winter Gem’ (we grow it) | Fast, 4 to 6 in a year | 4 ft x 4 ft | Outgrows a container quickly. |
Read that as years of comfort. A slow cultivar at half an inch to an inch a year will sit happily in a 30-inch planter for the better part of two decades. A fast one at four to six inches a year reaches four feet tall and four feet wide by fifteen years, and long before that it is root-bound, drying out in a day and needing a bigger container or a hard root prune.
So: for a planter you intend to leave alone, choose slow. For a piece you want at presence quickly and are willing to re-pot, fast is a reasonable trade, as long as you make it on purpose.
One caution about hardiness. Zone ratings are written for plants in the ground. A root ball in a container above ground is exposed on all sides and behaves roughly like one zone colder, which is why the zone-by-zone cultivar guide, written for boxwood planted in the ground, should be read one step conservatively for anything in a pot.
How big does the planter have to be?
Bigger than most people buy. Two separate numbers decide it, and only one of them is about the plant looking right.
The first is the root ball. Where we publish the figure, a mature live boxwood ships on a 24-inch root ball more often than on any other size, and that ball has to pass through the opening of the planter. A great many large planters narrow sharply at the mouth, so a container that measures nearly forty inches across its belly can have an opening of twenty-one. That is a real example from our own range, and it is the single most common way a planter that looked generous turns out to be unusable.
The second is the balance. A planted piece looks settled when the plant stands roughly one and a half times the height of the container, and reads as top-heavy much beyond that, which matters in wind as well as in a photograph.
Both of those are worked through properly, with the measurements and the arithmetic, in what size planter a topiary needs.
Watering, which is what actually kills them
Boxwood in the ground is drought-tolerant once established. Boxwood in a pot is not, and the reason is those fine roots: they colonise the ball they arrived on slowly, and until they have spread into the surrounding mix, the plant is drinking from a volume of soil much smaller than the container it sits in.
Water the root ball, not the pot. In the first season, soak the ball itself deeply and check it with a finger rather than trusting a schedule, because the surrounding mix can be damp while the ball at the centre is bone dry. That failure is common and it looks exactly like disease: dull foliage, then bronzing, then whole branches browning off from the inside.
The other half of the same problem is drainage. A container with no way out holds a reservoir at the bottom that the roots eventually reach, and boxwood roots in standing water rot. The maker does not publish drainage detail for these pieces, so ask us before you plant rather than after: we will check the piece you are looking at. Where a planter has no hole, the answer is either to drill one or to plant into a liner that lifts out, never to plant straight into a sealed container.
Feeding a boxwood in a container
A boxwood in open ground is fed twice a year, with a balanced feed, 10-10-10 to 14-14-14, in early March and again in October. In a container the same feed leaches out with every watering, so it wants feeding more often and more gently: a liquid feed at half strength through the growing season does more good than a heavy dose twice a year.
What it does not want is high nitrogen. Soft, fast growth on a boxwood is weak growth, it holds shape badly, and it is the growth that burns in a cold wind.
Winter in a container
The most winter-vulnerable plant we see is not a tender one. It is a boxwood that went into December in a dry pot.
An evergreen keeps losing water through its leaves all winter. When the root ball is frozen or simply dry, it cannot replace what it loses, and the plant desiccates. The damage shows in February and March as bronzing, and gardeners reliably blame the cold, when the cause was water in November.
So the winter routine is short. Water containers deeply into late autumn, right up until the ground freezes. Move the planter out of the worst of the wind if it is somewhere exposed, because wind drives that water loss harder than low temperature does. Where winters are severe, group containers together or lag the pot: it is the root ball you are insulating, not the foliage.
Two things not to do. Do not wrap the foliage in plastic, which cooks the plant on the first sunny day. And do not panic at bronzing on the side facing the winter sun, which is a normal reaction on several cultivars and greens up as soon as new growth comes.
Pruning, and holding the shape
Container boxwood is pruned on the same calendar as everything else we grow: the week of June 1, so that new growth has covered the cut leaf edges by the middle of August. A second light tidy in early autumn is fine. Cutting into winter is not, and neither is pruning freeze-burned tips before the last frosts have passed, because the damaged growth is protecting what is behind it.
A boxwood in a pot that is holding its shape and not putting on much size is not a plant in trouble. That is what a slow cultivar in a well-chosen container is supposed to look like.
What we grow, and what it arrives on
We grow and ship live boxwood as balls, cones, spirals, standards on a stem and tiered pieces, in the sizes listed on the live boxwood topiary pages. Mature specimens travel on a 24-inch root ball and go by freight; the smaller ones ship UPS in a box built for the weight.
The containers are a separate business and we are honest about it: we buy them in rather than make them. They are on the planters pages, and the ones that suit a boxwood best are the wide, straight-sided pieces rather than the dramatic narrow-mouthed jars.
If you are matching a specific plant to a specific planter, tell us the piece and we will measure the opening before you order rather than estimate it.
