Mature size & growth rate

How big does Pelargonium citronellum (Pelargonium citronellum) get?

Also called Citronella geranium, Mosquito plant, Lemon pelargonium.

More about pelargonium citronellum

About Pelargonium citronellum

Pelargonium citronellum · also called Citronella geranium, Mosquito plant · herb

Pelargonium citronellum is a robust scented geranium with rough, deeply lobed leaves that smell strongly of lemon-citronella when touched. Often sold as the 'mosquito plant', its fragrance does not actually repel insects in the air. A tall, vigorous South African species, it bears pink flowers and demands full sun, sharp drainage and a frost-free winter.

Mature size: 80-120 cm tall and 60-90 cm wide; among the larger scented geraniums and can reach 1.2 m or more if unpruned.

Watch for — Tall and leggy: Its natural vigour makes it sprawl if unchecked; prune and pinch in spring to maintain a bushy, well-branched shape.

Indoor size vs how big it gets in the wild

Pelargonium citronellum is a garden shrub whose final size is set more by your secateurs than by the plant — pruning, not luck, decides how big it gets. Indoors and in a pot, expect 80-120 cm tall and 60-90 cm wide. In the ground with no restriction it is a completely different plant — among the larger scented geraniums and can reach 1.2 m or more if unpruned. — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

Left unpruned it builds a woody framework that gets taller and wider every year; with annual pruning you hold it at whatever size suits the space.

Growth rate and years to mature

Pelargonium citronellum is a fast grower. Realistically, expect two to four years from a young plant to a room-filling specimen in good light. Its feeding profile backs this up: feed every 3-4 weeks in spring and summer with a balanced or high-potash liquid feed; this vigorous grower needs only moderate nitrogen. suspend feeding in autumn and winter.

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

How to keep pelargonium citronellum smaller

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

Prune pelargonium citronellum annually at the right time for its type — this is the primary, expected way to control its size.
Remove the oldest, thickest stems at the base each year to keep it open and within bounds.
Growing it in a large container rather than open ground naturally restricts the ultimate size.
Avoid heavy feeding if you want to limit growth — rich soil and lots of nitrogen drive bigger, faster shrubs.

The keep-it-smaller method, step by step

Prune at the right time. Time the cut to pelargonium citronellum's type (after flowering for many spring shrubs, late winter for summer-flowering ones) so you do not lose the next display.
Take out the oldest stems. Remove up to a third of the oldest, thickest stems at the base to renew the shrub and contain it.
Shorten the rest. Cut the remaining stems back to an outward-facing bud at the height and width you want.
Restrict the roots. For a permanent size cap, grow it in a large container rather than open ground.

How to grow pelargonium citronellum bigger or faster

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

Plant it in open ground in good soil — far more vigorous than a container-restricted plant.
Full sun (which it wants) plus an annual mulch and feed gives the strongest growth.
Water well through the first establishment years; a settled root system drives the fastest size gain.

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

When pelargonium citronellum outgrows the room (or the pot)

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

It shades or crowds neighbouring plants, or blocks a path it used to clear.
Bare, woody, unproductive centres with growth only on the outside — a sign it needs renovation pruning.
It has clearly exceeded the space you allotted and an annual trim no longer holds it.

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

Pelargonium citronellum size — frequently asked questions

How big does pelargonium citronellum get?

Pelargonium citronellum reaches 80-120 cm tall and 60-90 cm wide when grown indoors, and far larger where it grows unrestricted (among the larger scented geraniums and can reach 1.2 m or more if unpruned.). Left unpruned it builds a woody framework that gets taller and wider every year; with annual pruning you hold it at whatever size suits the space.

Is pelargonium citronellum slow or fast growing?

Pelargonium citronellum is a fast grower. Expect two to four years from a young plant to a room-filling specimen in good light. Pelargonium citronellum is a garden shrub whose final size is set more by your secateurs than by the plant — pruning, not luck, decides how big it gets.

How long does pelargonium citronellum take to reach full size?

Roughly two to four years from a young plant to a room-filling specimen in good light. Light, pot size and feeding move that timeline more than anything else.

How do I keep pelargonium citronellum smaller?

Prune pelargonium citronellum annually at the right time for its type — this is the primary, expected way to control its size. Remove the oldest, thickest stems at the base each year to keep it open and within bounds. Growing it in a large container rather than open ground naturally restricts the ultimate size. Avoid heavy feeding if you want to limit growth — rich soil and lots of nitrogen drive bigger, faster shrubs.

How can I make pelargonium citronellum grow bigger or faster?

Plant it in open ground in good soil — far more vigorous than a container-restricted plant. Full sun (which it wants) plus an annual mulch and feed gives the strongest growth. Water well through the first establishment years; a settled root system drives the fastest size gain.