Mature size & growth rate

How big does Faulkner box (Buxus microphylla 'Faulkner') get?

Also called Faulkner box, Faulkner boxwood, small-leaved box Faulkner.

More about faulkner box

About Faulkner box

Buxus microphylla 'Faulkner' · also called Faulkner box, Faulkner boxwood · flowering

Faulkner box is a compact, slow-growing cultivar of Japanese boxwood with dense, glossy, dark bluish-green foliage that holds its colour well in winter. It is notably more resistant to box blight than many common boxwoods, making it a reliable choice for formal topiary, balls, and low hedging.

Mature size: Up to 1.5 m tall and 1.5 m wide untrimmed; typically maintained at 30–80 cm as topiary

Indoor size vs how big it gets in the wild

Faulkner box is a tree at heart. Indoors a pot and your ceiling keep it to up to 1.5 m tall and 1.5 m wide untrimmed, but in the ground it is a different scale of plant entirely (typically maintained at 30–80 cm as topiary). Indoors and in a pot, expect up to 1.5 m tall and 1.5 m wide untrimmed. In the ground with no restriction it is a completely different plant — typically maintained at 30–80 cm as topiary — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

It gains real height on a trunk or main stem, adding a tier of leaves a year and eventually reaching for the ceiling — this is a plant you grow up, not out.

Growth rate and years to mature

Faulkner box is a slow grower. Realistically, expect a decade or more — slow growers like this add only a few centimetres a year, so expect 8-15+ years to reach their indoor ceiling. Its feeding profile backs this up: feed with a balanced slow-release granular fertiliser in early spring. a second light feed immediately after the main summer clip encourages dense regrowth. avoid nitrogen-heavy feeds after late july to prevent soft, frost-susceptible growth.

Want this turned into the right next pot at the right moment? The pot size calculator and the faulkner box repotting guide cover when and how much to size up — pot size is one of the biggest levers on how fast faulkner box grows.

How to keep faulkner box smaller

You are not stuck with the maximum size. For faulkner box specifically, these are the levers, in order of impact:

The decisive tool is the secateurs: faulkner box can be topped (cut the main growing tip) to cap its height and force a bushier, shorter shape.
Keeping it deliberately pot-bound in a snug container slows the whole plant and limits ultimate size.
Prune in spring so it heals fast; remove the tallest leader back to a node to reset the height.
Good news: slow growth means topping it once buys you years before it needs doing again.

The keep-it-smaller method, step by step

Pick the new height. Decide how tall you want faulkner box and find a leaf node or branch point just below that.
Top the main stem. Cut the main growing tip cleanly just above that node in spring; this permanently caps the height and forces side branches.
Keep the pot snug. Avoid jumping to a much bigger pot — a slightly restricted rootball keeps the whole plant smaller.
Maintain the shape. Prune back the tallest new leaders each spring to hold it at the height you chose.

How to grow faulkner box bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for faulkner box the accelerators are:

It already wants the bright light it needs; warmth, a yearly pot-up and spring-summer feed are the accelerators.
Pot up a size every year or two while young; restricted roots are the main thing holding height back.
Feed regularly through the growing season and keep it warm — height comes from sustained good conditions.

Light is almost always the ceiling. The faulkner box light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When faulkner box outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for faulkner box:

The top leaves pressing against or bent by the ceiling — the classic "this is now too tall indoors" sign.
It has to be moved away from a light source it has literally outgrown.
Roots filling the largest pot you can reasonably keep indoors — at that point it is top-or-prune or move it outside (if hardy).

If it is the pot rather than the room, it is a repotting job, not a goodbye — see the faulkner box repotting guide. If you want more of this plant instead of a bigger one, the faulkner box propagation guide turns prunings into new plants.

Faulkner box size — frequently asked questions

How big does faulkner box get?

Faulkner box reaches up to 1.5 m tall and 1.5 m wide untrimmed when grown indoors, and far larger where it grows unrestricted (typically maintained at 30–80 cm as topiary). It gains real height on a trunk or main stem, adding a tier of leaves a year and eventually reaching for the ceiling — this is a plant you grow up, not out.

Is faulkner box slow or fast growing?

Faulkner box is a slow grower. Expect a decade or more — slow growers like this add only a few centimetres a year, so expect 8-15+ years to reach their indoor ceiling. Faulkner box is a tree at heart. Indoors a pot and your ceiling keep it to up to 1.5 m tall and 1.5 m wide untrimmed, but in the ground it is a different scale of plant entirely (typically maintained at 30–80 cm as topiary).

How long does faulkner box take to reach full size?

Roughly a decade or more — slow growers like this add only a few centimetres a year, so expect 8-15+ years to reach their indoor ceiling. Light, pot size and feeding move that timeline more than anything else.

How do I keep faulkner box smaller?

The decisive tool is the secateurs: faulkner box can be topped (cut the main growing tip) to cap its height and force a bushier, shorter shape. Keeping it deliberately pot-bound in a snug container slows the whole plant and limits ultimate size. Prune in spring so it heals fast; remove the tallest leader back to a node to reset the height. Good news: slow growth means topping it once buys you years before it needs doing again.

How can I make faulkner box grow bigger or faster?

It already wants the bright light it needs; warmth, a yearly pot-up and spring-summer feed are the accelerators. Pot up a size every year or two while young; restricted roots are the main thing holding height back. Feed regularly through the growing season and keep it warm — height comes from sustained good conditions.