Mature size & growth rate

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

Also called Rheingold Arborvitae, Amber Globe Thuja.

More about rheingold arborvitae

About Rheingold Arborvitae

Thuja occidentalis 'Rheingold' · also called Rheingold Arborvitae, Amber Globe Thuja · flowering

A slow-growing dwarf conifer valued for warm amber-gold foliage that turns rich coppery-bronze in winter. Young plants carry soft juvenile foliage and form a rounded mound, maturing to a broad cone. It colours best in full sun and prefers moist, well-drained soil, making a striking low-maintenance accent for borders, rock gardens, and containers.

Mature size: About 0.9-1.2 m tall and 1.2-1.5 m wide over 10-15 years; slow.

Indoor size vs how big it gets in the wild

Rheingold Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to about 0.9-1.2 m tall and 1.2-1.5 m wide over 10-15 years, but in the ground it is a different scale of plant entirely (slow.). Indoors and in a pot, expect about 0.9-1.2 m tall and 1.2-1.5 m wide over 10-15 years. In the ground with no restriction it is a completely different plant — slow. — 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

Rheingold Arborvitae 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 once in early spring with a balanced slow-release or evergreen fertiliser. go light on nitrogen, which can dilute the amber colour and force soft growth; avoid late-season feeding.

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

How to keep rheingold arborvitae smaller

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

The decisive tool is the secateurs: rheingold 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.
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 rheingold 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 rheingold arborvitae bigger or faster

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

When rheingold arborvitae outgrows the room (or the pot)

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

Rheingold Arborvitae size — frequently asked questions

How big does rheingold arborvitae get?

Rheingold Arborvitae reaches about 0.9-1.2 m tall and 1.2-1.5 m wide over 10-15 years when grown indoors, and far larger where it grows unrestricted (slow.). 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 rheingold arborvitae slow or fast growing?

Rheingold Arborvitae 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. Rheingold Arborvitae is a tree at heart. Indoors a pot and your ceiling keep it to about 0.9-1.2 m tall and 1.2-1.5 m wide over 10-15 years, but in the ground it is a different scale of plant entirely (slow.).

How long does rheingold arborvitae 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 rheingold arborvitae smaller?

The decisive tool is the secateurs: rheingold 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. Good news: slow growth means topping it once buys you years before it needs doing again.

How can I make rheingold 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.