PlantLegit
Short answer: Planting them won't keep mosquitoes away. Iowa State, Clemson and UF/IFAS Extension all say the oils only help when leaves are crushed or extracted[1][2][3], and a field study found citronella geraniums didn't reduce bites[5]. What works: EPA-registered repellents and dumping standing water weekly[4].
Sources (6)
- [1] Iowa State University Extension: Mosquito Control – yardandgarden.extension.iastate.edu
- [2] Clemson HGIC: Can Plants Repel Problematic Insects? – hgic.clemson.edu
- [3] UF/IFAS (Aug 6, 2025): the myth of mosquito-repelling plants – blogs.ifas.ufl.edu
- [4] CDC: Preventing Mosquito Bites – cdc.gov
- [5] Schreiber & Cilek (1995), J. Am. Mosq. Control Assoc.: Failure of the "mosquito plant" Pelargonium × citrosum 'van Leenii' – researchgate.net
- [6] ASPCA Toxic and Non-Toxic Plants List
Checked 2026-10-15. Informational only, not legal or professional advice.
Plant by plant: myth vs. evidence, with pet toxicity
| Plant | What the evidence says | Pets (ASPCA[6]) |
|---|---|---|
| Citronella geranium / "mosquito plant" Pelargonium × citrosum | Myth as a planted repellent: a Florida field study found no difference in mosquito landings with plants present[5] | ASPCA: toxic to dogs, cats |
| Citronella grass Cymbopogon nardus | Source of citronella oil, but a plant on the patio has no effect; leaves must be crushed[1] | see ASPCA |
| Lemongrass Cymbopogon citratus | Oil protected test subjects about 40 minutes in studies; the planted plant does not repel[2] | ASPCA: toxic to dogs, cats |
| Rosemary Rosmarinus officinalis | Oil protected about 15 minutes; planted rosemary does not[2] | ASPCA: non-toxic |
| Lavender Lavandula angustifolia | Oils must be extracted to work; planted lavender does little[3] | ASPCA: toxic to dogs, cats |
| Basil Ocimum basilicum | Same: aromatic, but scent dissipates; not shown to repel as a planting[2][3] | ASPCA: non-toxic |
| Mint Mentha spp. | Same as above[3] | ASPCA: toxic to dogs, cats |
| Marigold — French/African Tagetes spp. | UF/IFAS lists marigolds among plants whose oils must be extracted to work (species not specified)[3] | not in ASPCA list |
| Pot marigold (calendula) Calendula officinalis | Same UF/IFAS caveat; included because both are sold as marigold[3] | ASPCA: non-toxic |
| Catnip Nepeta cataria | Named by Clemson among touted plants; no landscape-planting evidence[2] | ASPCA: toxic to cats |
| Lemon thyme / scented geranium Thymus, Pelargonium | Iowa State: "ineffective as repellents"[1] | see ASPCA |
What actually works
- CDC: use an EPA-registered repellent with DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), PMD or 2-undecanone. OLE and 2-undecanone are plant-derived[4]. Note OLE is a registered product — not the same as a eucalyptus plant.
- CDC: do not use OLE or PMD on children under 3[4].
- CDC: once a week, empty and scrub, turn over, cover or throw out anything holding water — tires, buckets, toys, pools, birdbaths, flowerpot saucers[4].
- CDC: "We do not know the effectiveness of non-EPA registered insect repellents, including some natural repellents."[4]
- Iowa State: citronella candles cut biting about 40% only if you stand directly in the smoke[1].
- Clemson: rubbing essential oils on skin can irritate, especially in high concentrations[2].
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