Mature size & growth rate

How big does Kimberly queen fern (Nephrolepis obliterata) get?

Also called sword fern, erect sword fern.

About Kimberly queen fern

Nephrolepis obliterata · also called sword fern, erect sword fern · houseplant

Kimberly queen fern is an upright Australian relative of the Boston fern, more tolerant of dry air and tidier in growth habit. Pet-safe and a popular porch and indoor fern. Less needle-drop than Boston fern.

Nephrolepis obliterata, the Australian sword fern, native to Australia and adapted to warm, humid conditions; hardy outdoors only in USDA zones 9-11.

Distinctive upright, narrow, sword-shaped fronds forming a dense bushy clump (about 60-90cm), and it rarely sheds leaflets, unlike the messier drooping Boston fern; reported non-toxic to cats and dogs.

Mature size: 60-90 cm tall and wide

Watch for — Slow growth: Underfeeding or insufficient light.

Sources: provenwinners.com, gardenia.net

Indoor size vs how big it gets in the wild

Kimberly queen fern stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward. Indoors and in a pot, expect 60-90 cm tall and wide. A pot, your light levels and a little pruning are what set the final size in a home, far more than the plant's theoretical potential.

Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Growth rate and years to mature

Kimberly queen fern 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: half-strength balanced feed monthly in growing season.

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

How to keep kimberly queen fern smaller

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

Divide the clump every year or two — splitting kimberly queen fern is the main way to control its spread and refresh it.
Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump.
Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

The keep-it-smaller method, step by step

Lift the whole plant. Slide kimberly queen fern out of its pot in spring when the clump has filled it.
Split the clump. Tease or cut the rootball into two or more sections, each with healthy roots and growth.
Repot one division. Put a single division back in the original pot to reset it to a smaller size; pot or give away the rest.
Remove offsets as they form. Through the year, detach new runners or pups to stop it spreading again.

How to grow kimberly queen fern bigger or faster

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

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger.
Brighter light speeds up clump and offset production noticeably.
Leave plantlets and offsets attached and feed through the growing season for the fastest spread.

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

When kimberly queen fern outgrows the room (or the pot)

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

The clump bulging over the pot rim or splitting the pot — the cue to divide, not to find a bigger room.
A dense centre that goes bare or tired while the edges keep spreading.
Runners or offsets escaping across the shelf or into neighbouring pots.

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

Kimberly queen fern size — frequently asked questions

How big does kimberly queen fern get?

Kimberly queen fern reaches 60-90 cm tall and wide when grown indoors. Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Is kimberly queen fern slow or fast growing?

Kimberly queen fern is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Kimberly queen fern stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward.

How long does kimberly queen fern 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 kimberly queen fern smaller?

Divide the clump every year or two — splitting kimberly queen fern is the main way to control its spread and refresh it. Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump. Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

How can I make kimberly queen fern grow bigger or faster?

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger. Brighter light speeds up clump and offset production noticeably. Leave plantlets and offsets attached and feed through the growing season for the fastest spread.