Mature size & growth rate

How big does Spilanthes (Acmella oleracea) get?

Also called Toothache Plant, Buzz Buttons, Paracress.

More about spilanthes

About Spilanthes

Acmella oleracea · also called Toothache Plant, Buzz Buttons · herb

Spilanthes, the toothache plant, is a low, spreading tender annual grown for its gold-and-red 'eyeball' flower buds and tingling, numbing leaves. Chewing a bud produces a buzzing, saliva-inducing sensation from spilanthol, used traditionally for oral pain. It loves heat, sun, and moist fertile soil, sprawling into a dense edible groundcover and flowering nonstop until frost.

Mature size: 25-35 cm tall and 30-45 cm wide, spreading.

Watch for — Aphids and spider mites: Soft new growth attracts aphids, and hot dry air brings mites. Inspect tips and leaf undersides, rinse off pests, and maintain humidity.

Indoor size vs how big it gets in the wild

Spilanthes 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 25-35 cm tall and 30-45 cm wide, spreading.. 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

Spilanthes is a moderate grower. Realistically, expect a single growing season — it reaches full size in one year, then is done. Its feeding profile backs this up: moderate feeder. mix compost in at planting and give a balanced liquid feed every 3-4 weeks through the growing season to sustain continuous flowering and leaf growth.

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

How to keep spilanthes smaller

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

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

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

When spilanthes outgrows the room (or the pot)

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

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

Spilanthes size — frequently asked questions

How big does spilanthes get?

Spilanthes reaches 25-35 cm tall and 30-45 cm wide, spreading. 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 spilanthes slow or fast growing?

Spilanthes is a moderate grower. Expect a single growing season — it reaches full size in one year, then is done. Spilanthes 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 spilanthes 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 spilanthes smaller?

Choose a compact or dwarf variety of spilanthes 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 spilanthes 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.