Mature size & growth rate

How big does Pyramidalis Arborvitae (Thuja occidentalis 'Pyramidalis') get?

Also called Pyramidal Arborvitae, Pyramid Thuja.

More about pyramidalis arborvitae

About Pyramidalis Arborvitae

Thuja occidentalis 'Pyramidalis' · also called Pyramidal Arborvitae, Pyramid Thuja · flowering

A vigorous, upright evergreen forming a dense, narrow pyramid of bright green foliage, long used for tall hedges, screens, and formal accents. Faster-growing than many cultivars, it quickly provides privacy and windbreak cover. It performs best in full sun with consistently moist, well-drained soil, holds a tidy conical shape, and tolerates a wide range of climates.

Mature size: About 4.5-6 m tall and 1.2-1.8 m wide; faster and larger than most cultivars.

Indoor size vs how big it gets in the wild

Pyramidalis Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to about 4.5-6 m tall and 1.2-1.8 m wide, but in the ground it is a different scale of plant entirely (faster and larger than most cultivars.). Indoors and in a pot, expect about 4.5-6 m tall and 1.2-1.8 m wide. In the ground with no restriction it is a completely different plant — faster and larger than most cultivars. — 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

Pyramidalis Arborvitae is a fast grower. Realistically, expect two to four years from a young plant to a room-filling specimen in good light. Its feeding profile backs this up: feed once in early spring with a balanced slow-release or evergreen fertiliser; hedge and screen plantings benefit from a second light feed in early summer. avoid late-season nitrogen that encourages frost-tender growth.

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

How to keep pyramidalis arborvitae smaller

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

The decisive tool is the secateurs: pyramidalis arborvitae 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.
Expect to top or hard-prune it every year or two — left alone it heads for the ceiling.

The keep-it-smaller method, step by step

Pick the new height. Decide how tall you want pyramidalis arborvitae 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 pyramidalis arborvitae bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for pyramidalis arborvitae 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 pyramidalis arborvitae light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When pyramidalis arborvitae outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for pyramidalis arborvitae:

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 pyramidalis arborvitae repotting guide. If you want more of this plant instead of a bigger one, the pyramidalis arborvitae propagation guide turns prunings into new plants.

Pyramidalis Arborvitae size — frequently asked questions

How big does pyramidalis arborvitae get?

Pyramidalis Arborvitae reaches about 4.5-6 m tall and 1.2-1.8 m wide when grown indoors, and far larger where it grows unrestricted (faster and larger than most cultivars.). 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 pyramidalis arborvitae slow or fast growing?

Pyramidalis Arborvitae is a fast grower. Expect two to four years from a young plant to a room-filling specimen in good light. Pyramidalis Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to about 4.5-6 m tall and 1.2-1.8 m wide, but in the ground it is a different scale of plant entirely (faster and larger than most cultivars.).

How long does pyramidalis arborvitae take to reach full size?

Roughly two to four years from a young plant to a room-filling specimen in good light. Light, pot size and feeding move that timeline more than anything else.

How do I keep pyramidalis arborvitae smaller?

The decisive tool is the secateurs: pyramidalis arborvitae 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. Expect to top or hard-prune it every year or two — left alone it heads for the ceiling.

How can I make pyramidalis arborvitae 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.