Jump To Section
What’s the Difference Between Citronella Grass and Citronella Geranium?
The term “citronella plant” can refer to two different types of plants: citronella grass (Cymbopogon nardus and Cymbopogon winterianus) and a scented geranium variously known as citrosa or mosquito plant (Pelargonium citrosum).
Citronella grass is an inedible grass related to lemongrass. It is the main source of citronella oil, an essential oil used as a non-toxic insect repellent. Citronella geraniums, on the other hand, do not contain citronella oil—but they have a strong citronella-like scent.
Despite their similar smells, citronella grass and citronella geraniums look very different: Citronella grass is a bushy green grass with purple-pink base stems, while the citronella geranium has broad, fuzzy leaves that are deeply serrated.
Are Citronella Plants an Effective Mosquito Repellant?
Although citronella oil is an effective mosquito repellent, citronella grass itself won’t do much to keep mosquitos out of your garden; you can release the citronella oil from the plant by crushing the leaves, but even then, you need a significant quantity of citronella oil to discourage insects. Citronella geraniums, which lack citronella oil, are even less effective at deterring mosquitos.
Both citronella grass and citronella geraniums are great ornamentals—grow them for the lovely scent they release in the garden—but don’t expect a reduction in mosquitos.
How to Grow Citronella Geraniums
Citronella geraniums are a great addition to your garden, notable for their lemony scent. Like other members of the geranium family, they’re typically purchased as small plants from garden centers and aren’t usually grown from seed. If you know someone with a citronella plant, you can propagate citronella from stem cuttings. To propagate from a cutting:
- Take a cutting. Use a good pair of scissors or garden pruners to make the cleanest possible cuts. You need at least two nodes—the bumps on stems and branches where leaves and side shoots emerge—on each cutting. That’s because you need at least one node below the soil or water (this is where roots will form) and one node above (where new shoots and leaves will grow).
- Remove all but two leaves from the stem. Too much greenery may drain the moisture needed to grow roots. If the cutting dries out before roots form, you’re out of luck (the remaining leaves should be at the tip of the cutting—if they are large, cut them down to the size of a bottle cap).
- Use rooting compound to promote growth. You may wish to invest in a jar of rooting compound, which contains naturally occurring hormones that stimulate root growth. Otherwise, stick the cutting in a container of moist potting soil. The cutting should take root in a couple of weeks.
- Ensure that the mature plant gets sufficient sunlight. Place your citronella plant in full sun or a partially shaded area that receives at least six hours of sunlight each day. Citronella geraniums will survive outdoors year-round as a perennial in USDA plant hardiness zones 9b through 11—i.e. much of the West Coast, the Southwest, and the Southeast of the United States. In other zones, they can be brought inside during the winter or left outside as an annual.
- Water your citronella geranium regularly. Although mature geraniums are considered drought-tolerant, it's a good idea to water your citronella plants regularly. To check whether your citronella geranium needs water, feel the top inch of soil with your finger. If it feels dry, give it a good soak. Don't be afraid to prune your citronella geranium to encourage a bushy appearance if you want it to remain small enough to keep indoors.
3 Tips for Growing Citronella Grass
Known as the “true citronella” plant due to its high concentration of citronella essential oil, the tropical citronella grass is less common in home gardens than the more widely available citronella geranium. If you do manage to find small potted citronella plants at your local garden center, keep these tips in mind when planting them in your garden:
- Make sure you have enough space for citronella grass. Citronella grass can grow up to 6 feet tall and 6 feet wide and should be spaced accordingly.
- Plant citronella glass in filtered sunlight. In warm climates, plant citronella grass in loamy soil in an area that receives filtered sunlight. In colder climates, plant citronella grass in large containers and move inside before the first frost.
- Water frequently. Indoors and out, citronella grass requires near-daily watering to mimic the humid climate of its native tropical South and Southeast Asia.
Think Like a Pro
Community activist and self-taught gardener Ron Finley shows you how to garden in any space, nurture your plants, and grow your own food.View Class
Grow your own food with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community - and the world - a better place.