Mature size & growth rate

How big does Rimu (Dacrydium cupressinum) get?

Also called Red Pine, New Zealand Red Pine.

More about rimu

About Rimu

Dacrydium cupressinum · also called Red Pine, New Zealand Red Pine · flowering

Rimu is an iconic New Zealand conifer with pendulous, fine-textured weeping foliage in shades of bronze-green and striking small red seed cones. One of New Zealand's most prized timber and ornamental trees, slow-growing and very long-lived. Podocarpus-family fruits should be kept away from pets.

Mature size: Up to 50 m in native forest; typically 6-15 m in temperate garden cultivation

Watch for — Slow growth: Naturally very slow-growing; patience is essential — ensure consistent moisture and organic mulch for best results.

Indoor size vs how big it gets in the wild

Rimu is a tree at heart. Indoors a pot and your ceiling keep it to up to 50 m in native forest, but in the ground it is a different scale of plant entirely (typically 6-15 m in temperate garden cultivation). Indoors and in a pot, expect up to 50 m in native forest. In the ground with no restriction it is a completely different plant — typically 6-15 m in temperate garden cultivation — 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

Rimu 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: apply a slow-release, ericaceous fertiliser in early spring to maintain soil acidity. in naturally acidic, fertile soils, supplemental feeding is rarely necessary. avoid alkaline fertilisers which can cause nutrient lock-out.

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

How to keep rimu smaller

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

The decisive tool is the secateurs: rimu 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 rimu 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 rimu bigger or faster

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

When rimu outgrows the room (or the pot)

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

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

Rimu size — frequently asked questions

How big does rimu get?

Rimu reaches up to 50 m in native forest when grown indoors, and far larger where it grows unrestricted (typically 6-15 m in temperate garden cultivation). 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 rimu slow or fast growing?

Rimu 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. Rimu is a tree at heart. Indoors a pot and your ceiling keep it to up to 50 m in native forest, but in the ground it is a different scale of plant entirely (typically 6-15 m in temperate garden cultivation).

How long does rimu 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 rimu smaller?

The decisive tool is the secateurs: rimu 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 rimu 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.