Mosquito repellent plants — 10 tested picks

Mosquito repellent plants — 10 picks tested (research-backed)

Garden centres in May are full of pots labelled "mosquito plant," "citronella geranium" and "anti-mosquito basil." The marketing implies that planting them will clear mosquitoes from a patio. That is not what the research shows. This guide reviews the ten most-marketed mosquito repellent plants against peer-reviewed entomology research from Iowa State, USDA and university extension services, separates what works (some plants, rubbed on skin) from folklore (most claims of "repels mosquitoes when planted"), and gives you the realistic protocol that actually keeps a garden bite-free.

Try Growli: Snap a photo of a plant and Growli will tell you what it actually does. Honest answers — no marketing hype.

Why "mosquito repellent plants" mostly don't work as planted

Mosquitoes find hosts using CO2, body heat, skin volatiles like lactic acid, and visual cues. A planted herb sitting in a pot emits some volatile oil, but the concentration in ambient air at biting distance is far too low to disrupt host-seeking behaviour. The same plant's leaves, crushed and rubbed on skin, can briefly mask those cues — that's why some traditional uses persist.

Three honest tests you can apply to any "mosquito plant" claim:

1. Is the active compound the oil, or the leaf surface? Almost always the oil. So passive emission from a plant in a pot is far weaker than topical application.
2. Is there peer-reviewed evidence? Most marketing relies on a single 2001 catnip paper (Iowa State, Peterson and Coats) extrapolated far beyond what it demonstrated.
3. Is the EPA / UK HSE willing to register it as a topical repellent? For most "mosquito plants," no. The only major exception is oil of lemon eucalyptus (Corymbia citriodora), which the CDC accepts as effective at concentrations of 30%.

Safety boilerplate: Always read repellent product labels and follow manufacturer's PPE, dosage and re-entry guidance. Pesticide and repellent approvals change — confirm via US EPA or UK HSE before use. Do not apply oil of lemon eucalyptus to children under 3 years old.

10 mosquito repellent plants reviewed

1. Catnip (Nepeta cataria) — research-backed when applied to skin

A 2001 Iowa State University study by entomologists Chris Peterson and Joel Coats found that nepetalactone, the essential oil in catnip, was about ten times more effective at repelling Aedes aegypti mosquitoes than DEET in laboratory bioassays. A 2024 follow-up in Scientific Reports using a Y-tube olfactometer confirmed catnip essential oil has strong repellent activity.

Important caveats:

• The studies measured catnip essential oil applied directly, not catnip plants growing in a bed.
• Nepetalactone is highly volatile, so the active window is shorter than DEET-based products.
• There is no EPA-registered topical catnip repellent available commercially — extracted nepetalactone is still being developed.

Practical takeaway: plant catnip if you like cats and pollinators; crush fresh leaves and rub on bare skin for short outdoor stretches. Don't expect a planted catnip pot to clear mosquitoes from a patio.

2. Lemon eucalyptus (Corymbia citriodora) — the one EPA-approved option

Oil of lemon eucalyptus (OLE), refined from the leaves of this Australian eucalyptus, is the only plant-derived topical repellent the CDC and EPA accept as effective. The active ingredient PMD (para-menthane-3,8-diol) provides protection comparable to lower-concentration DEET in clinical trials.

• Commercial products: Repel Lemon Eucalyptus, OFF! Botanicals (in some markets).
• Apply at 30% concentration following label directions; not for children under 3.
• Growing the plant itself does not give meaningful protection.

Safety note: Read the product label and follow the manufacturer's PPE and reapplication schedule. Confirm registration status via US EPA or UK HSE before use.

3. Citronella geranium / "mosquito plant" (Pelargonium citrosum) — weak evidence

Sold heavily under names like "citrosa" or "mosquito plant." A widely cited Guelph University trial in 1996 by Matsuda et al. found Pelargonium citrosum "did not repel Aedes mosquitoes" as a planted specimen. Crushed leaves rubbed on skin provide minor short-lived protection because they contain citronellal — but at far lower concentrations than the citronella grass (Cymbopogon nardus) used in real citronella candles.

Verdict: good-looking houseplant; weak mosquito plant. Don't pay a premium for the "mosquito" label.

4. Lemongrass (Cymbopogon citratus) and citronella grass (Cymbopogon nardus)

The actual source of commercial citronella oil. Crushed leaves contain citronellal at higher concentrations than citrosa geranium. Studies show citronella-based candles and topical preparations can reduce mosquito biting locally for short periods, but a single plant in a pot has limited effect at conversation distance.

• Grow as an annual outside zone 9 in the US.
• Use the harvested leaves for cooking or to crush and rub on skin briefly.

5. Lemon balm (Melissa officinalis)

Contains citronellal and citral. Crushed leaves on skin give a brief repellent effect. Easy hardy perennial; great for tea. Don't expect planted lemon balm to deter mosquitoes from a garden — the field evidence is weak.

6. Basil (Ocimum basilicum, Ocimum tenuiflorum)

Some lab studies show basil essential oils have mosquito repellent activity against Aedes and Anopheles species, particularly holy basil (Ocimum sanctum). As with the others, this works for the oil or for crushed leaves, not for a plant standing in a pot. Worth growing for kitchen use and as a companion plant for tomatoes.

7. Peppermint (Mentha x piperita)

Menthol-rich oils have demonstrated mosquito repellent activity in laboratory tests. Plant in pots — mint spreads aggressively. Crushed leaves rubbed on skin give a brief refreshing effect that may modestly repel mosquitoes for a short window.

8. Lavender (Lavandula angustifolia)

Linalool, one of lavender's main oils, has repellent activity in lab studies. As a planted specimen, the effect is minimal. Grow for the flowers, pollinators and aroma; not for mosquito control.

9. Marigold (Tagetes species)

Folk reputation as a mosquito repellent is strong; peer-reviewed evidence is weak. Some research shows marigold extracts have larvicidal activity against mosquito larvae in standing water, but no good evidence that planted marigolds reduce adult biting around a garden. Best uses: nematode suppression in vegetable beds and trap-cropping for aphids.

10. Rosemary (Salvia rosmarinus)

Lab studies show rosemary essential oil has some repellent activity. The same caveat applies — as a planted shrub the effect is minor. Grow rosemary for cooking, ornamental value and as a deer- and rabbit-resistant evergreen.

What actually keeps a garden bite-free

Mosquito control works in this order, by research-backed effectiveness:

1. Eliminate breeding sites

Mosquitoes breed in still water. Most species can complete their life cycle in a teaspoon of water in a week.

• Empty saucers, buckets, wheelbarrows, plant pots, blocked gutters, tarp folds and bird baths twice a week.
• Drill drainage holes in anything that holds rainwater.
• Treat ornamental ponds with Bacillus thuringiensis israelensis (Bti) "mosquito dunks" — biological larvicide that kills mosquito larvae without harming fish, birds or pollinators.

2. Use topical repellents

• DEET (20–30%) — gold standard, long-lasting.
• Picaridin (20%) — DEET-equivalent in CDC reviews, lower skin feel.
• Oil of lemon eucalyptus / PMD (30%) — plant-derived, CDC-approved, not for children under 3.
• IR3535 (20%) — alternative active.

3. Reduce attractants

• Wear light-coloured loose long sleeves at dusk.
• Avoid heavy perfumed lotions when sitting outdoors.
• Run a strong fan on the patio — mosquitoes are weak fliers and avoid moving air.

4. Use plants strategically

Plant your collection of catnip, citronella grass, lemon balm and basil within reach of seating so leaves are easy to crush and rub on skin. Position them around bare-skin contact zones rather than expecting a planted border to protect a whole garden.

Prevention going forward

1. Drain standing water every 5–7 days — single most effective home mosquito control tactic.
2. Use Bti dunks in ponds and rain barrels monthly through the mosquito season.
3. Apply topical repellent at dusk — that's when most biting species feed.
4. Run a patio fan on still summer evenings.
5. Crush and rub leaves of catnip or lemon balm on bare skin when you need a short-term plant-based boost.

Related articles

• Companion planting guide
• Garden pest identification — complete guide
• How to grow basil
• How to grow rosemary
• How to grow mint

Reviewed and updated by the Growli editorial team. For questions about anything here, open Growli and ask — or email hello@getgrowli.app.