Mature size & growth rate

How big does Lemon Basil (Ocimum × africanum 'Mrs. Burns') get?

Also called Mrs. Burns Lemon Basil.

More about lemon basil

About Lemon Basil

Ocimum × africanum 'Mrs. Burns' · also called Mrs. Burns Lemon Basil · herb

Lemon basil is a citrus-scented hybrid basil whose leaves carry a bright lemon aroma from high citral content, prized in Thai and Southeast Asian cooking. 'Mrs. Burns' is a vigorous heirloom strain with larger leaves and strong fragrance. Grow it as a tender warm-season annual in full sun, pinching often to delay its quick flowering.

Mature size: 30-50 cm tall and 25-40 cm wide

Indoor size vs how big it gets in the wild

Lemon Basil 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 30-50 cm tall and 25-40 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

Lemon Basil 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 every 3-4 weeks with a balanced liquid fertiliser at half strength during growth. moderate feeding keeps the citral aroma concentrated; overdoing nitrogen produces bland, lush leaves.

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

How to keep lemon basil smaller

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

Choose a compact or dwarf variety of lemon basil 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 lemon basil bigger or faster

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

When lemon basil outgrows the room (or the pot)

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

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

Lemon Basil size — frequently asked questions

How big does lemon basil get?

Lemon Basil reaches 30-50 cm tall and 25-40 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 lemon basil slow or fast growing?

Lemon Basil is a fast grower. Expect a single growing season — it reaches full size in one year, then is done. Lemon Basil 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 lemon basil 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 lemon basil smaller?

Choose a compact or dwarf variety of lemon basil 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 lemon basil 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.