Soil & potting mix
Best soil for Pelargonium citronellum (Pelargonium citronellum)
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.
Preferred mix: Free-draining loam or potting mix with added grit or perlite
Why pelargonium citronellum needs this mix
Pelargonium citronellum is a hungry, thirsty leafy herb — it wants a rich, moisture-retentive but free-draining loam, well fed and never baked dry.
- Pelargonium citronellum grows fast and puts on a lot of soft leaf, so it draws heavily on both nutrients and water — a lean mix simply cannot keep up.
- Plenty of organic matter holds moisture evenly, which prevents the stress problems (bolting, bitterness, blossom-end rot) that come from a drying-then-flooding cycle.
- It still needs structure: rich does not mean airless, so grit, perlite or leaf mould keeps roots oxygenated.
For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.
What goes wrong with the wrong mix
The wrong soil is one of the most common reasons pelargonium citronellum struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- A poor, thin or sandy mix starves pelargonium citronellum — growth stalls, leaves pale, and the plant bolts to seed early.
- A heavy, compacted, badly drained soil rots the roots and brings fungal problems despite all the feeding.
- Letting a rich mix dry to dust then drowning it causes the classic moisture-stress disorders this crop is prone to.
Under-feeding and inconsistent moisture. Pelargonium citronellum needs genuinely rich soil plus steady watering — most disappointing crops come down to one or both being short.
pH — does it matter for pelargonium citronellum?
Pelargonium citronellum does best around pH 6.0-7.0 (slightly acidic to neutral). It is worth a cheap soil test for an outdoor bed; very acidic soil benefits from a little lime well before planting.
If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.
DIY mix vs a bagged one
For containers a good multipurpose or vegetable compost works for pelargonium citronellum with extra feed through the season. For beds, the real win is digging in plenty of well-rotted compost or manure — that beats any bag.
Drainage and the pot
Rich but free-draining is the target: raised beds and large containers both deliver it. Mulch heavily to even out moisture and roughly halve how often you water.
Pelargonium citronellum is usually grown for a single season, so "repotting" means starting fresh each year — never reuse exhausted, disease-prone compost for the same crop family. When the time comes, our repotting guide for pelargonium citronellum covers the timing and technique step by step.
Pelargonium citronellum soil — frequently asked questions
What is the best soil mix for pelargonium citronellum?
3 parts rich peat-free compost : 1 part well-rotted garden compost or manure : 1 part perlite or grit (containers) / leaf mould (beds). Pelargonium citronellum grows fast and puts on a lot of soft leaf, so it draws heavily on both nutrients and water — a lean mix simply cannot keep up.
Can I use normal potting soil for pelargonium citronellum?
A poor, thin or sandy mix starves pelargonium citronellum — growth stalls, leaves pale, and the plant bolts to seed early. For containers a good multipurpose or vegetable compost works for pelargonium citronellum with extra feed through the season. For beds, the real win is digging in plenty of well-rotted compost or manure — that beats any bag.
Does pelargonium citronellum need a special pH?
Pelargonium citronellum does best around pH 6.0-7.0 (slightly acidic to neutral). It is worth a cheap soil test for an outdoor bed; very acidic soil benefits from a little lime well before planting.
Should I buy a bagged mix or make my own for pelargonium citronellum?
For containers a good multipurpose or vegetable compost works for pelargonium citronellum with extra feed through the season. For beds, the real win is digging in plenty of well-rotted compost or manure — that beats any bag.
How often should I refresh the soil for pelargonium citronellum?
Pelargonium citronellum is usually grown for a single season, so "repotting" means starting fresh each year — never reuse exhausted, disease-prone compost for the same crop family. Rich but free-draining is the target: raised beds and large containers both deliver it. Mulch heavily to even out moisture and roughly halve how often you water.
Keep reading
- Pelargonium citronellum care — the full brief (light, water, humidity, problems, pet safety)
- How often to water pelargonium citronellum — the schedule the mix feeds into
- Repotting pelargonium citronellum — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Should I water my plant? The simple check first
- Why is my plant wilting? Wet vs dry diagnosis
- Underwatered plant — signs and how to rehydrate it
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- Best soil for herb garden
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- All 5561 soil and potting-mix guides in the Growli library