How to Grow and Care for Citronella Grass

Citronella grass, Cymbopogon nardis is a native grass of Sri Lanka and a major source for the essential oil citronella. Steam distillation, a labor intensive process, is used to extract this potent oil in demand for its mosquito repelling properties. But you don't have to distill it to reap the bug repellent benefits. You can grow citronella grass in your own back yard if you live in USDA growing zones 9 or 10. If your climate is cooler, grown this grass as an annual or in a pot that you can bring indoors to overwinter.

To release the insect repelling fragrance from your crash, simply crush some of the leaves. You can also rub crushed leaves directly on your skin. It is advisable to test a small patch first to make sure you don't experience any irritation or allergic reaction.

Citronella is a tall, fast-growing grass that release a signature lemony scent when crushed. which mosquitos and other insects dislike. Besides discouraging pesky insects that can spoil your backyard BBQ, citronella grass acts as a wonderful decorative grass. This plant can grow up to 6 feet tall and 4 feet wide, providing a large focal piece. Citronella boasts lance-shaped blades of grass and produces light brown, spiked flowers from summer to fall. 

Citronella Grass Care

Citronella grass is hardy only to 32 F which means it is a perennial only in warm climates. No matter where you live and whether you plant in the ground or in a pot, this grass needs plenty of water and sunshine. If you do plant outside, you may want to remove the seed heads after flowering to prevent the spread of unwanted seedlings in the garden.

Light

Citronella grass grows best in mostly sunny areas where it receives a break from direct sun exposure in the afternoon. Too much direct sun can burn the foliage.

Soil

Well-draining soil is key to growing healthy citronella grass. Since this plant needs plenty of water, well-draining soil will help prevent problems like root rot. Moist, loamy soil is best, but this grass is quite adaptable to other soil types and can grow well under a variety of conditions.

Water

Because citronella grass originates in areas with high humidity and plenty of rainfall, it has substantial watering requirements. Depending on the climate, you may need to water your grass every day.

For example, keeping your citronella grass indoors in a container will mean that your plant will have lower humidity levels and a smaller amount of soil to draw moisture from. In this situation, you will need to water every day. If your grass is planted outdoors in a humid environment, you will not need to water as much. Therefore, your watering schedule will depend on the amount of rain and the humidity levels of the plant's environment.  

Temperature and Humidity

Citronella grass can be grown as a perennial in USDA hardiness zones 10 to 12, but many use it as an annual in other zones. However, citronella grass will not handle cold temperatures for long periods of time. It does not survive temperatures below 32 F.

If you would like to keep your citronella alive but live in an area with long, cold winters, try keeping your citronella grass in a pot and bringing it indoors before the first frost. Cut the grass back to about 3 inches above the soil line and place it near a sunny window or under grow lights. Your plant can overwinter inside your warm home and will be big and beautiful by the time spring rolls around. As for humidity, citronella grass loves moisture and thrives in humid climates.  

Fertilizer

A fertilizer high in nitrogen is perfect for citronella grass. It only needs fertilizer once a year, so feed in the spring for best results and to encourage healthy growth. 

Propagating Citronella Grass 

Because citronella grass is a clumping plant, dividing it in the spring is the best and easiest way to propagate this plant:

1. Using a sharp shovel or spade, slice through the plant and its root system at the point you would like to divide it. 
2. Slowly work the roots of the divided section away from the parent plant. 
3. Add soil to the parent plant where needed.  
4. Move your divided citronella grass to a new location and water it regularly.  

Potting and Repotting Citronella Grass

Citronella grass can easily be grown in a pot, giving you maximum flexibility to rearrange the plant as needed or bring it inside during colder winter weather.

Because of the large size and fast-growing nature of citronella grass, even starter plants need a relatively large pot. Depending on the size of the plant you purchase, starting your citronella grass in a gallon size pot is generally appropriate.

When choosing a pot, be sure it has a drainage hole to prevent too much water retention. Set your potted grass in a sunny area with some afternoon shade. Be sure to water regularly, as potted plants need more frequent watering. 

Over time, you'll notice that the citronella grass has run out of room to spread—meaning it's time to repot. To do so, tip your pot on its side and gently slide the grass out. You can use a hand spade to loosen soil around the edges but avoid tugging at the foliage which will cause it to break. Once you've freed the plant, repot in a larger container with a quality potting mix and give the plant a drink.

Citronella Grass vs. Lemongrass

Citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) are often confused. Though they look similar, it's important to distinguish between these two ornamental grasses since lemongrass is edible, while citronella grass is not. If you are looking to keep the mosquitos away, only citronella will do the job. 

To determine whether a plant is citronella grass or lemongrass, take a look at the foliage color. Lemongrass is completely green, with no other colors present. Citronella grass, on the other hand, will have red-tinted pseudo-stems, or overlapping leaves, that form a stem-like base.