Mature size & growth rate

How big does Tobacco Root (Valeriana edulis) get?

Also called Tobacco Root, Edible Valerian, Hairy Valerian.

More about tobacco root

About Tobacco Root

Valeriana edulis · also called Tobacco Root, Edible Valerian · herb

A North American native perennial of mountain meadows and prairies, valued by many Indigenous peoples for its large, edible taproot, traditionally slow-baked for up to two days to neutralise bitter compounds and eaten as a vegetable or made into bread. Produces tall airy clusters of tiny white flowers above basal rosettes.

Mature size: 50–90 cm tall, 30–45 cm spread; taproot to 90 cm deep

Watch for — Poor seed germination: The species is dioecious, so both male and female plants are needed for seed production. Seed viability drops quickly; sow fresh seed in autumn and overwinter in a cold frame. Expect slow, erratic germination in spring.

Indoor size vs how big it gets in the wild

Tobacco Root 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 50–90 cm tall, 30–45 cm spread. In the ground with no restriction it is a completely different plant — taproot to 90 cm deep — 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

Tobacco Root 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 balanced slow-release fertiliser or compost in early spring. a phosphorus and potassium-rich feed in early summer supports taproot development. avoid heavy nitrogen applications which promote excessive leaf growth at the expense of the edible root.

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

How to keep tobacco root smaller

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

Divide the clump every year or two — splitting tobacco root 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 tobacco root 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 tobacco root bigger or faster

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

When tobacco root outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for tobacco root:

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

Tobacco Root size — frequently asked questions

How big does tobacco root get?

Tobacco Root reaches 50–90 cm tall, 30–45 cm spread when grown indoors, and far larger where it grows unrestricted (taproot to 90 cm deep). 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 tobacco root slow or fast growing?

Tobacco Root is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Tobacco Root 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 tobacco root 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 tobacco root smaller?

Divide the clump every year or two — splitting tobacco root 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 tobacco root 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.