Mature size & growth rate

How big does Wart Fern (Microsorum scolopendria) get?

Also called Wart Fern, Oak Leaf Fern, Climbing Bird's Nest Fern.

More about wart fern

About Wart Fern

Microsorum scolopendria · also called Wart Fern, Oak Leaf Fern · houseplant

The wart fern is a creeping epiphytic fern from Pacific and tropical-Asian forests, named for the wart-like sori dotting the undersides of its glossy, deeply lobed fronds. It spreads by a long-running surface rhizome rather than a crown, climbing logs and walls. Grown indoors it rewards bright-indirect light, steady warmth, high humidity, and an open, bark-rich mix.

Mature size: Fronds typically 30-75 cm long indoors; the rhizome can spread well over a metre across a mount or wide pan over time.

Watch for — Scale and mealybugs: Sap-suckers hide along the rhizome and frond undersides among the sori; wipe off and treat with horticultural soap, checking new growth weekly.

Indoor size vs how big it gets in the wild

Wart Fern 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 typically 30-75 cm long indoors. In the ground with no restriction it is a completely different plant — the rhizome can spread well over a metre across a mount or wide pan over time. — 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

Wart Fern is a fast grower. Realistically, expect one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. Its feeding profile backs this up: feed monthly through spring and summer with a balanced liquid fertiliser diluted to half strength. ferns are salt-sensitive, so flush the mix occasionally and pause feeding in autumn and winter.

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

How to keep wart fern smaller

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

Trim the longest vines back to the length you want — wart fern 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.
Expect to tidy it every few weeks in summer — this is a fast vine that will sprawl if left.

The keep-it-smaller method, step by step

Decide the length you want. Pick the point each vine of wart fern 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 wart fern bigger or faster

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

When wart fern outgrows the room (or the pot)

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

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

Wart Fern size — frequently asked questions

How big does wart fern get?

Wart Fern reaches fronds typically 30-75 cm long indoors when grown indoors, and far larger where it grows unrestricted (the rhizome can spread well over a metre across a mount or wide pan over time.). 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 wart fern slow or fast growing?

Wart Fern is a fast grower. Expect one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. Wart Fern 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 wart fern take to reach full size?

Roughly one to three growing seasons — fast vines can add a metre or more of stem in a single good summer. Light, pot size and feeding move that timeline more than anything else.

How do I keep wart fern smaller?

Trim the longest vines back to the length you want — wart fern 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. Expect to tidy it every few weeks in summer — this is a fast vine that will sprawl if left.

How can I make wart fern 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.