Mature size & growth rate

How big does Quaking Grass (Briza media) get?

Also called quaking grass, trembling grass, doddering dillies.

More about quaking grass

About Quaking Grass

Briza media · also called quaking grass, trembling grass · flowering

Quaking grass is a dainty, cool-season perennial grass famous for its heart-shaped, locket-like flower spikelets that dangle on hair-fine stems and tremble with the slightest breeze. Forming low tufts of blue-green foliage, it suits wildflower meadows, gravel gardens and naturalistic borders. The papery, shimmering seedheads dry beautifully and are prized for cut and dried arrangements.

Mature size: Foliage tuft 15-30 cm tall; airy flowering stems reach 45-75 cm (about 1.5-2.5 ft) tall and 30 cm wide.

Watch for — Flopping in rich soil: Lush, lax growth that splays open results from over-rich or over-watered conditions; grow lean and sunny to keep stems wiry and upright.

Indoor size vs how big it gets in the wild

Quaking Grass 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 foliage tuft 15-30 cm tall. In the ground with no restriction it is a completely different plant — airy flowering stems reach 45-75 cm (about 1.5-2.5 ft) tall and 30 cm wide. — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

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

Quaking Grass 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: needs no feeding and actually prefers lean soil; fertiliser produces lax, floppy growth and fewer of the prized dancing seedheads. skip feeding entirely in average ground.

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

How to keep quaking grass smaller

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

Divide the clump every year or two — splitting quaking grass 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 quaking grass 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 quaking grass bigger or faster

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

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger.
Good light plus regular feeding maximises offset and runner production.
Leave plantlets and offsets attached and feed through the growing season for the fastest spread.

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

When quaking grass outgrows the room (or the pot)

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

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

Quaking Grass size — frequently asked questions

How big does quaking grass get?

Quaking Grass reaches foliage tuft 15-30 cm tall when grown indoors, and far larger where it grows unrestricted (airy flowering stems reach 45-75 cm (about 1.5-2.5 ft) tall and 30 cm wide.). 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 quaking grass slow or fast growing?

Quaking Grass is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Quaking Grass 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 quaking grass 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 quaking grass smaller?

Divide the clump every year or two — splitting quaking grass 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 quaking grass grow bigger or faster?

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger. Good light plus regular feeding maximises offset and runner production. Leave plantlets and offsets attached and feed through the growing season for the fastest spread.