Mature size & growth rate

How big does Shiso (Perilla frutescens var. crispa) get?

Also called shiso, perilla, Japanese basil.

More about shiso

About Shiso

Perilla frutescens var. crispa · also called shiso, perilla · herb

Shiso is a fast-growing annual mint relative prized in Japanese, Korean, and Vietnamese cooking for its ruffled green or deep-purple leaves and complex flavour of mint, basil, and anise. It grows easily from seed in warm weather, reaching knee-height in a season, and self-sows readily. Both leaf colours are ornamental as well as edible, thriving in sun to part shade.

Mature size: 45-90 cm tall and 30-45 cm wide

Indoor size vs how big it gets in the wild

Shiso 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 45-90 cm tall and 30-45 cm 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.

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

Shiso 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: feed lightly every 3-4 weeks during active growth with a balanced or nitrogen-leaning fertiliser to keep leaf production going, or work compost into the bed at planting. avoid over-feeding, which can soften flavour.

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

How to keep shiso smaller

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

Choose a compact or dwarf variety of shiso 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 shiso bigger or faster

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

When shiso outgrows the room (or the pot)

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

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

Shiso size — frequently asked questions

How big does shiso get?

Shiso reaches 45-90 cm tall and 30-45 cm wide 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 shiso slow or fast growing?

Shiso is a fast grower. Expect a single growing season — it reaches full size in one year, then is done. Shiso 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 shiso 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 shiso smaller?

Choose a compact or dwarf variety of shiso 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 shiso 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.