Mature size & growth rate

How big does Common Nardoo (Marsilea drummondii) get?

Also called Common Nardoo, Nardoo, Australian Nardoo.

More about common nardoo

About Common Nardoo

Marsilea drummondii · also called Common Nardoo, Nardoo · houseplant

Common Nardoo is an Australian aquatic fern with distinctive four-lobed, clover-like fronds that float on still or slow-moving water. Grown in tubs or pond margins, it roots into submerged mud and tolerates both shallow water and periodically dry conditions. Best suited to warm climates; bring indoors in frost-prone areas. Historically a First Nations food plant when prepared correctly.

Mature size: Fronds to 20 cm (8 in) above the water surface; rhizomes spread indefinitely across soft substrate

Watch for — Frost damage: Fronds blacken and collapse below 5°C (41°F). In frost-prone regions, move container indoors before first frost and keep the substrate moist; rhizomes and sporocarps may survive mild frost but regrowth is slow.

Indoor size vs how big it gets in the wild

Common Nardoo does not get tall — it gets long. Size here is about stem length and how you train or cut it, not how much floor it claims. Indoors and in a pot, expect fronds to 20 cm (8 in) above the water surface. In the ground with no restriction it is a completely different plant — rhizomes spread indefinitely across soft substrate — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

Growth shows up as lengthening stems that trail down or climb up a support; the plant can be kept tiny or grown metres long from the exact same root system.

Growth rate and years to mature

Common Nardoo 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 slow-release aquatic fertiliser tablet pushed into the substrate once in spring and again in early summer. avoid high-nitrogen liquid feeds that leach into the water and trigger algal blooms. no feeding needed in autumn or winter.

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

How to keep common nardoo smaller

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

Trim the longest vines back to the length you want — common nardoo takes hard cutting well and bushes out from the cut.
Cut just above a leaf node; each trimmed stem usually branches into two, so pruning makes it fuller, not sparser.
The cuttings root easily in water or mix, so "keeping it smaller" doubles as free new plants.
A trim once or twice a season is usually enough to hold its length.

The keep-it-smaller method, step by step

Decide the length you want. Pick the point each vine of common nardoo should stop — you can be aggressive; it regrows readily.
Cut just above a node. Snip about 0.5 cm above a leaf node so the stem branches there instead of dying back.
Root the cuttings. Drop the trimmed pieces in water or mix — they root in 2-4 weeks and can fill the same pot for a bushier look.
Repeat as it runs. Re-trim whenever it overshoots; regular light pruning keeps it both smaller and fuller.

How to grow common nardoo bigger or faster

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

Good light plus a moss pole or trellis triggers the longest, fastest, largest-leaved growth.
Give it something to climb — many vines grow far faster and bigger up a support than trailing.
Feed through spring and summer and keep it consistently watered while it is actively running.

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

When common nardoo outgrows the room (or the pot)

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

Vines pooling on the floor or wrapping past where you want them — purely a trimming cue, not a repot one.
Bare, leggy stems with leaves only at the tips (usually a light problem, not a size one).
A tangled mass that has outrun its support and needs cutting back and re-training.

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

Common Nardoo size — frequently asked questions

How big does common nardoo get?

Common Nardoo reaches fronds to 20 cm (8 in) above the water surface when grown indoors, and far larger where it grows unrestricted (rhizomes spread indefinitely across soft substrate). Growth shows up as lengthening stems that trail down or climb up a support; the plant can be kept tiny or grown metres long from the exact same root system.

Is common nardoo slow or fast growing?

Common Nardoo is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Common Nardoo does not get tall — it gets long. Size here is about stem length and how you train or cut it, not how much floor it claims.

How long does common nardoo 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 common nardoo smaller?

Trim the longest vines back to the length you want — common nardoo takes hard cutting well and bushes out from the cut. Cut just above a leaf node; each trimmed stem usually branches into two, so pruning makes it fuller, not sparser. The cuttings root easily in water or mix, so "keeping it smaller" doubles as free new plants. A trim once or twice a season is usually enough to hold its length.

How can I make common nardoo grow bigger or faster?

Good light plus a moss pole or trellis triggers the longest, fastest, largest-leaved growth. Give it something to climb — many vines grow far faster and bigger up a support than trailing. Feed through spring and summer and keep it consistently watered while it is actively running.