Mature size & growth rate

How big does Chinese Arborvitae (Thuja orientalis) get?

Also called Chinese Arborvitae, Oriental Arborvitae, Biota, Oriental Thuja.

More about chinese arborvitae

About Chinese Arborvitae

Thuja orientalis · also called Chinese Arborvitae, Oriental Arborvitae · flowering

Chinese Arborvitae (now often reclassified as Platycladus orientalis) is a versatile, drought-tolerant evergreen conifer from northeastern China and Korea. Its distinctive vertically held, fan-like foliage sprays set it apart from other arborvitaes. Highly adaptable to heat, drought, and alkaline soils, it is widely used in warm-climate hedging, topiary, and specimen planting.

Mature size: 5–15 m tall, 2–5 m wide; growth rate moderate (15–30 cm per year); dwarf cultivars widely available at 0.5–3 m

Indoor size vs how big it gets in the wild

Chinese Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to 5–15 m tall, 2–5 m wide, but in the ground it is a different scale of plant entirely (growth rate moderate (15–30 cm per year); dwarf cultivars widely available at 0.5–3 m). Indoors and in a pot, expect 5–15 m tall, 2–5 m wide. In the ground with no restriction it is a completely different plant — growth rate moderate (15–30 cm per year); dwarf cultivars widely available at 0.5–3 m — 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

Chinese Arborvitae is a moderate grower. Realistically, expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Its feeding profile backs this up: apply a balanced slow-release fertiliser in early spring to encourage consistent growth. on fertile soils, annual feeding is not necessary. in poor or alkaline soils, an acidifying fertiliser or chelated micronutrient supplement improves foliage colour. avoid late-season nitrogen, which delays hardening.

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

How to keep chinese arborvitae smaller

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

The decisive tool is the secateurs: chinese 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 chinese 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 chinese arborvitae bigger or faster

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

When chinese arborvitae outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for chinese 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 chinese arborvitae repotting guide. If you want more of this plant instead of a bigger one, the chinese arborvitae propagation guide turns prunings into new plants.

Chinese Arborvitae size — frequently asked questions

How big does chinese arborvitae get?

Chinese Arborvitae reaches 5–15 m tall, 2–5 m wide when grown indoors, and far larger where it grows unrestricted (growth rate moderate (15–30 cm per year); dwarf cultivars widely available at 0.5–3 m). 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 chinese arborvitae slow or fast growing?

Chinese Arborvitae is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Chinese Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to 5–15 m tall, 2–5 m wide, but in the ground it is a different scale of plant entirely (growth rate moderate (15–30 cm per year); dwarf cultivars widely available at 0.5–3 m).

How long does chinese arborvitae take to reach full size?

Roughly three to six years to reach mature indoor size, gaining a steady amount each growing season. Light, pot size and feeding move that timeline more than anything else.

How do I keep chinese arborvitae smaller?

The decisive tool is the secateurs: chinese 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 chinese 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.