Citronella, lemongrass, and palmarosa quick facts

What are citronella, lemongrass, palmarosa?

Citronella, lemongrass, and palmarosa, are all common names for grasses in the genus Cymbopogon, a genus that includes more than 70 species of tropical grasses that produce essential oils. Essential oils are oils containing volatile compounds that give off distinctive scents. Some species of Cymbopogon are grown commercially as herbs or as sources of essential oils. The main commercially exploited species are:

• Citronella or citronella grass: Ceylon citronella (Cymbopogon nardus) and Java citronella (Cymbopogon winterianus). These grasses should not be confused with the citronella plant (Pelargonium citronellum, a type of geranium). The essential oils from these plants, sold as citronella oil, contain various concentrations of geraniol, citronellal, and cintronellol.
• Lemongrass: West Indian lemongrass (Cymbopogon citratus), East Indian lemongrass (Cymbopogon flexuosus), and Jammu lemongrass (Cymbopgon pendulus). The essential oils in these grasses contain a compound called citral, which is also found in the fragrant peels of citrus fruits. 
• Palmarosa: Cymbopogon martini var. motia. The essential oil in this grass is largely made of up geraniol and is considered to have a scent similar to roses (Rosa). 

Other species, such as karnkusa grass (Cymbogon iwarancusa), are also used as sources of essential oils or as herbs or medicinal plants. Some other Cymbopogon oils are gingergrass oil (Cymbopogon martini var. sofia), karnkusa oil (Cymbogon iwarancusa), and jamrosa or jamarosa oil (C. iwarancusa x C. nardus)

Where did citronella, lemongrass, and palmarosa come from?

Cymbopogon is native to broad regions of Africa, Oceania, and large parts of southern Asia ranging from Turkey and the Sinai and Arabian peninsulas to southern China, North and South Korea, and Japan and regions to the south. The genus has been introduced to large parts of the tropical to subtropical Americas.

How are citronella, lemongrass, and palmarosa used?

Cultivated species of Cymbopogon are most important as sources of essential oils. Some of their oils are bottled and sold directly to consumers for aromatherapy and folk medicinal purposes. Much of the essential oil from Cymbopogon plants, however, is used in the food, fragrance, and cosmetics industries, as well as for other industrially produced products.

Citronella oil in particular is used in "natural" insect repellants and other insect-repelling products, like candles. Citronella oil usually comes from citronella grass rather than the citronella plant (Pelargoniium citronellum).

Lemongrass is used as an herb (a flavoring ingredient) in certain Asian cuisines, or it may be dried and used in herbal teas. Lemongrass is also sometimes grown as an ornamental.

Plant material left over after the essential oils have been extracted from plant tissues can be used as animal feed, fertilizer, or for other purposes. 

How are citronella grass, lemongrass, and palmarosa grown?

These grasses are grown in cultivated fields and are often propagated asexually from pieces of plants. Palmarosa may be cultivated from seed or collected from the wild.

Cymbopogon grasses are harvested by cutting the plants above their bases and collecting the leaves and other aboveground parts (if they have been allowed to develop). Cymbopogon grasses can be cut and allowed to regrow several times during the same growing season. The same crop may be harvested over several growing seasons before it needs to be replanted.

Where are citronella grass, lemongrass, and palmarosa grown?

Statistics on cultivation or collection of these grasses and production of essential oils are not as firm as those available for major crop plants like maize and sugarcane. Citronella oil is largely produced in China and Indonesia, although it also comes from many other tropical countries in the Americas, Africa, and Asia. Lemongrass oil is produced in Brazil, Guatemala, China, India, and other countries. Palmarosa oil is produced in India and other tropical countries.