7 Best Natural Mosquito Repellent: Plants, Herbs, Dried Fruits

Shopping around for natural mosquito-repelling plants? Some of the most popular natural mosquito repellents in Singapore are namely citronella-scented geranium (Pelargonium citrosum) and the rose-scented geranium (Pelargonium graveolens) – both dubbed mosquito plants as their scents are believed to ward off mosquitoes.

Here, eight local mosquito-repellent plants you can quite easily find in plant nurseries:

• Rose geranium
• Citronella geranium
• Lemon balm
• Rosemary
• Citronella
• Lavender
• Lemongrass
• Peppermint

According to Far East Flora's nursery sales and marketing director Peter Cheok, the essential oils in these plants are common ingredients in mosquito-repelling sprays.

Are Mosquito Repellent Plants Effective?

Botanist Shawn Lum says that while there is some evidence that selected plant essential oils and other compounds have insect-repellent properties, this does not necessarily mean that having the plants in one's compound will repel mosquitoes.

Repellent compounds released when leaves are crushed

Dr Lum, a senior lecturer from the Asian School of the Environment at Nanyang Technological University (NTU), says: "Some repellent compounds are only released when the leaves are crushed or burnt."

Even then, their effect may not last long.

Organic farmer Alexius Yeo, 31, who grew a mosquito plant and six pots of lemongrass in the garden of his parents' terrace house last year, found that when he crushed the leaves of the mosquito plant and lemongrass and rubbed them all over his skin, the mosquitoes stayed away longer.

The director of CarbonInQ, which runs nature-based education programmes, says: "But the smell went off and, after a while, the mosquitoes came back."

Professor Jorgen Schlundt, a food safety expert from the School of Chemical and Biomedical Engineering at NTU, says that, so far, there has been no scientific evidence that mosquito-repellent plants can bring about a significant drop in a person's risk of getting Zika or dengue.

Dr Lum adds: "That said, there is no harm in growing 'mosquito-repelling plants' at home."

Let's dive into the eight natural mosquito repellents that you can use at home:

1. Citronella Geranium, Rose Geranium

Crushed leaves of the Pelargonium citrosum seem to offer short-term relief from mosquitoes.

Some studies show that it has 30 to 40 per cent of the repelling power of Deet.

Deet (N, N-Diethyl-meta-toluamide) is a synthetic chemical that has been shown to be effective in repelling mosquitoes.

Another species of the same family, Pelargonium graveolens (pictured), is also sold here for its repellent properties.

Place a few pots together or occasionally rub the leaves to trigger the release of essential oils. Before rubbing crushed leaves on your skin, test them on a small spot first. Essential oils may cause some people to break out in rashes.

Rose or citronella geranium plants are available at $5 to $8 for a pot from World Farm, Far East Flora, or Candy Floriculture.

2. Basil

Basil plants are among the most pungent herbs. They are one of the few herbs which give off a scent without their leaves being crushed.

For temporary protection in the garden, rub some leaves on your skin to release the essential oils.

Basil potted plants are available at $5 to $8 per pot from World Farm, Katong Flower Shop, Candy Floriculture.

Read Also: Hike in Demand for Mosquito-Repelling Plants as Zika Virus Surfaces

3. Lemon Balm

Crushing the leaves of this herb and rubbing them on your skin supposedly provides a measure of protection against mosquito bites.

Fresh Lemon Balm potted plants are priced at $8 per pot from World Farm and Candy Floriculture.

4. Dried Lavender Flowers

An easier, lower maintenance way is to buy dried lavender flowers from health or scent shops, and make a potpourri bag or pouch out of them, or place one to two teaspoons into a small glass.

Place a glass of these flowers in each room, on the floor, near where our legs might be at a study table, for example.

Hang potpourri bags behind doors, where there might be mosquitoes because they like dark places.

A small pouch of these lavender flowers can also be put on each bed.

Read More: How to grow Lavender in Singapore's climate?

5. Lemongrass

Tie a whole piece of lemongrass with a string. Make six of these and hang them around the home.

Replace the lemongrass when the smell is gone.

Alternatively, purchase some dried lemongrass, lemongrass extracts, or essential oils to keep the smell longer lasting.

6. Dried Orange Peel

Buy dried orange peel from grocery shops. Place a piece in a small dish or glassware. Put these in every room, living room, dining room, bathrooms, balcony and the kitchen.

Replace the orange peel once the smell is gone.

7, Night Lights

If the mozzies are really bothering you or your child, sleep with the night light on. Mosquitoes dislike brightness and are less likely to come round.

Vice versa, mozzies prefer dark and stale nooks. So, if your wardrobe or study table has dark and messy corners, these may just be hotspots for the mosquitoes to congregate.

8. Switch on the Fan

Aha! Common sense. Where there's wind, it becomes more difficult for mosquitoes to land on human flesh to feed on our blood. It's simple, they'll get blown away by the gusts of wind before they get to their dinner.

PlantZom spray traps and kills mosquitoes

Candy Floriculture plans to sell a chemical solution called PlantZom to customers at $30 a bottle.

Invented three years ago by two chemists from a home-grown chemical formulation company, it has been offered through a spraying service to hotels, condominiums and companies.

Mr Edwin Chan, 44, one of the chemists who invented it, claims that when sprayed on plants, the chemical develops an invisible web which traps and kills mosquitoes within six hours after they land on the plant.

PlantZom, he claims, lingers around longer – at least 14 days, unlike conventional insecticides which last only about three days.

This article first appeared on The Straits Times.