By Jason Knight
There are a variety of plants that repel mosquitoes, including both wild and cultivated species. Almost anywhere you go, it is reasonable to find several plant species that you can use to ward off these pesky critters. Plant-based mosquito repellents are especially useful for people who spend a great deal of time in the wilderness.
It is important to note that it is compounds found within the plants that do the repelling. These compounds need to be released from the plant to unlock the mosquito-repelling qualities. Depending on the species of plant, they can be released by either crushing, drying, or infusing the plant into an oil or alcohol base that can be applied to skin, clothing, or living spaces. Others are best used as as a smudge, which releases the compounds in a smoke. Just standing near living plants that repel mosquitoes is often not effective.
Below are separate lists of wild and cultivated plants that repel mosquitoes:
Citronella Grass (Cymbopogon nardus) is the most popular cultivated plant used for repelling mosquitoes. Its oil, citronella oil, is the primary ingredient in most natural insect repellents sold in stores. Products applied to the skin are most effective. It grows in tropical regions.
Catnip (Nepeta cataria) is a common garden plant that can be used to repel mosquitoes. The crushed plant can be applied directly to the skin or the dried plant can be infused in an oil, such as olive oil. There is an interesting article about research conducted on the mosquito-repelling qualities of catnip.
Additional cultivated plants that repel mosquitoes:
Peppermint (Mentha piperita)
Rosemary (Rosmarinus officinalis)
Marigolds (Tagetes spp.)
Lemon balm (Melissa officinalis)
Garlic (Allium sativum)
Clove (Syzygium aromaticum)
Eucalyptus (Eucalyptus spp.)
Tea tree (Melaleuca alternifolia)
Lavendar (Lavandula angustifolia)
Vanilla Leaf (Achlys triphylla) is a plant native to the northwest and Japan. Indigenous peoples were known to hang bundles of the dried plants in and around their dwellings to keep mosquitoes and flies away. The plant can be rubbed on the skin fresh or dried to deter mosquitoes. I think its interesting that it often grows in shady, moist areas - the very places where mosquitoes can be the thickest.
Sagebrush, Wormwood, and Mugwort (Artemisia spp.) are in the same genus (plant grouping). All of these species can be used as an aromatic smudge that is known to be a very effective mosquito repellent. The crushed leaves can also be applied directly to the skin. These species grow in the drier habitats of the west, including the plains, deserts, and mountainous regions.
Pineapple weed (Matricaria matricarioides) (pictured above) is a common weedy species that grows all over North America. It can be found growing in lawns, edges of roads, and other disturbed areas. The aromatic crushed plant can be applied to the skin to help repel mosquitoes.
Additional wild plants known to repel mosquitoes:
Nodding onion (Allium cernuum)
Wild bergamot (Mondarda fistulosa)
Snowbrush (Ceonothus velutinus)
Sweetfern (Comptonia peregrina)
Cedars (Thuja spp.)
Its important to note that insect repellents applied to the skin generally only last one to two hours. Frequent re-application is necessary. Also, when utilizing wild plants, internally or externally, always be sure to correctly identify the plant you are going to use. It is best to utilize field guides and work with someone who knows the plant well to avoid accidentally using a poisonous look-alike.
In addition to using mosquito repelling plants, you may want to consider some other factors that can help keep mosquitoes away. Mosquitoes find their prey by following carbon dioxide and other components that animals breath out. Many outdoors-people have noticed that mosquitoes have a greater attraction to people that have been eating processed, sugary foods, and less attracted to people eating more of a natural diet such as whole grains, fruits, and vegetables. The processed food diet may make your odor and blood chemistry more attractive to mosquitoes. You can choose to eat less processed foods and sugars during the mosquito season. Additionally, diets high in garlic and onions have been noted to help reduce the attraction of mosquitoes.
When it is mosquito season, you can also choose to camp and hike away from their core habitat, areas of standing water. Instead, you can camp in places away from water with a breeze, which can help keep mosquitoes at a minimum. At home you can minimize mosquitoes by eliminating their breeding areas (standing water), such as old tires, buckets, trash cans, or anything that holds standing water.
References: Foster 1990, Pojar 1994, Turner 1998.
Courses on Uses of Wild Plants: