Mature size & growth rate

How big does Red Valerian (Centranthus ruber) get?

Also called red valerian, Jupiter's beard, kiss-me-quick.

More about red valerian

About Red Valerian

Centranthus ruber · also called red valerian, Jupiter's beard · flowering

Centranthus ruber is a fast, free-flowering perennial bearing dense clusters of scented red, pink or white blooms from late spring into autumn. It thrives in poor, alkaline, free-draining soil and full sun, famously colonising walls, gravel and chalk. Easy and pollinator-friendly, it self-seeds enthusiastically and can naturalise aggressively in mild climates.

Mature size: 60-90 cm tall and wide

Watch for — Floppy, leggy growth: Caused by rich soil, shade or feeding. Grow hard in poor, sunny, well-drained sites and cut back after the first flush.

Indoor size vs how big it gets in the wild

Red Valerian 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

Red Valerian 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: essentially none. it flowers best in poor soil; feeding produces soft, floppy growth at the expense of bloom. skip fertiliser entirely on lean ground.

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

How to keep red valerian smaller

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

Divide the clump every year or two — splitting red valerian 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 red valerian 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 red valerian bigger or faster

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

When red valerian outgrows the room (or the pot)

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

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

Red Valerian size — frequently asked questions

How big does red valerian get?

Red Valerian 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 red valerian slow or fast growing?

Red Valerian is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Red Valerian 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 red valerian 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 red valerian smaller?

Divide the clump every year or two — splitting red valerian 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 red valerian 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.