Garden Myths - Learn the truth about gardening

Mosquito Plant, Pelargonium Citrosum – The Citrosa Plant

The mosquito plant, Pelargonium Citrosum , also called the citrosa plant or citronella scented geranium, is highly recommended for keeping mosquitoes away. This plant is marketed as being specifically developed to continually give off a mosquito repelling scent. Turns out you can grow this plant in many gardens.

The mosquito plant has been confused by some in the horticulture industry, and falsely called the citronella plant. In Citronella Plant keeps Mosquitoes Away, I explained and clarified this mixup.


Mosquito Plant (Pelargonium'Citrosum')

Mosquito Plant (Pelargonium’Citrosum’)

Mosquitoes and Fragrant Geraniums

Pelargonium Citrosum is a strongly scented geranium that is reported to be very effective at keeping mosquitoes away. The University of Guelph tested the mosquito plant to validate the stated claims.

The researchers placed human subjects in a wooded area containing lots of mosquitoes. They then counted the number of mosquito bites each group of people received. People were randomly divided into 3 groups. One group tested DEET, another control group used water as a repellent, and a third group used water and sat beside a mosquito plant.

The experiment had a variety of built in controls to ensure that they tested both males and females, both of varying size and age. Tests were repeated to produce statistically sound data.

Deet provided greater than 90% protection after 8 hours.

People sitting beside the mosquito plant had the same number of mosquito bites as people who were treated with water. That is to say – the plant had no effect.

The researchers commented that “during field evaluations, mosquitoes were regularly observed landing and resting  on the mosquito plant, indicating a lack of repellancy”.

Mosquito Plant Does Not Work

The results were quite clear. The mosquito plant does not work.

Pelargonium Citrosum is quite fragrant, but it did not work at keeping mosquitoes away. What about other fragrant plants – do they work? I’ve discussed that in Mosquitoes Repelled by Fragrant Plants.


1) Field Evaluation of Citrosa Plant ‘Pelargonium Citrosum’, as a repellant against Mosquitoes;

2) Photo Source: Mokkie

If you like this post, please share .......
Robert Pavlis
Editor of
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

I hope you find Garden Myths an educational site that helps you understand your garden better.

One Response to 'Mosquito Plant, Pelargonium Citrosum – The Citrosa Plant'

  1. Roger Brook says:

    I am told some euphorbias keep moles away. Anyone want to try? No I thought not!