Mature size & growth rate

How big does Turnip (Brassica rapa) get?

Also called white turnip, salad turnip, neep (Scotland).

About Turnip

Brassica rapa · also called white turnip, salad turnip · edible

Turnips are quick cool-season brassicas grown for tender roots (50-60 days) and edible greens. Sweet and mild when young; woody if overripe. Pet-safe — dogs can eat both root and tops in moderation.

A swollen-root form of Brassica rapa, the same Old World species as bok choy and Chinese cabbage, long grown across temperate Europe and Asia as a fast cool-season root and green.

Pull turnips young at 2-3 inches across for sweet, tender roots; a heavy straw mulch over fall plantings extends the harvest into early winter.

Mature size: 20-30 cm tall

Sources: extension.umn.edu, hgic.clemson.edu, extension.illinois.edu

Indoor size vs how big it gets in the wild

Turnip reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back. Indoors and in a pot, expect 20-30 cm tall. 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.

It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Growth rate and years to mature

Turnip is a fast grower. Realistically, expect a single growing season — it reaches full size in one year, then is done. Its feeding profile backs this up: light balanced feed at planting; avoid heavy nitrogen.

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

How to keep turnip smaller

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

Choose a compact or dwarf variety of turnip from the start — that is the most reliable size control for an annual.
Grow it in a smaller container to naturally limit how large it gets.
For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier.
Sow a little later or space plants closer if you specifically want smaller individual plants.

How to grow turnip bigger or faster

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

Full sun, warm soil and steady water are what drive a crop to full size fastest.
Sow at the right time for your zone so it gets the whole season to size up.
Feed appropriately for the crop and never let it check (stall) from drought or cold.

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

When turnip outgrows the room (or the pot)

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

It sprawls beyond its bed or container before harvest — usually a spacing or support issue.
It flops or needs staking once it hits full height.
Once it has fruited or bolted, it is at its final size for good — the next plant is a new sowing.

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

Turnip size — frequently asked questions

How big does turnip get?

Turnip reaches 20-30 cm tall when grown indoors. It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Is turnip slow or fast growing?

Turnip is a fast grower. Expect a single growing season — it reaches full size in one year, then is done. Turnip reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back.

How long does turnip take to reach full size?

Roughly a single growing season — it reaches full size in one year, then is done. Light, pot size and feeding move that timeline more than anything else.

How do I keep turnip smaller?

Choose a compact or dwarf variety of turnip from the start — that is the most reliable size control for an annual. Grow it in a smaller container to naturally limit how large it gets. For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier. Sow a little later or space plants closer if you specifically want smaller individual plants.

How can I make turnip grow bigger or faster?

Full sun, warm soil and steady water are what drive a crop to full size fastest. Sow at the right time for your zone so it gets the whole season to size up. Feed appropriately for the crop and never let it check (stall) from drought or cold.