Citronella oil, the savior in the fight against the mighty mosquito! If you live in a warm, humid climate, you've heard of citronella as an oil used in a burner, candle, or cosmetic lotion applied to the skin to repel mosquito bites. But do you know where it comes from? Well, let me introduce you to the citronella plant Cymbopogon nardus!
The citronella plant is not to be confused with another lemony "alleged" insect repellant plant, the scented geranium Pelargonium citrosum. Scented geranium, sometimes called citronella geranium, is pleasing to the eye and smells amazing, but it does no good in the fight against pests.
The true citronella plant is a large, tufted perennial weed that grows up to 1.8m tall and 1.2m wide in the right conditions. It is the oil contained in the leaves that repels insects and it can only be harvested by crushing the leaves. The existence of these grasses alone will not deter mosquitoes.
Citronella oil has a long tradition of medicinal use, e.g. B. to treat lice, parasites or worms and to relieve migraines and fever. Its antibacterial, antimicrobial, anti-inflammatory and antifungal properties make it useful in both cleaning and cosmetic products, giving them a distinctive lemon scent.
Quick care instructions
The citronella plant is a herbaceous, lemon-scented species. Source: Ahmad Fuad Morad
|common names||Citronella Plant, Midge Plant, Citronella Grass, Geranium Grass and Nardus Grass|
|Scientific name||Cymbopogon nardus, Cymbopogon winterianus|
|Height & Spread||6ft x 4ft|
|Bright||Full sun to part shade|
|water||Consistent regular watering|
|Pests & Diseases||leaf rot|
All about the citronella plant
The top of a citronella grass flower stalk. Source: dr Alexey Yakovlev
If you find a plant with the botanical name Cymbopogon nardus or Cymbopogon winterianus in garden centers, rest assured that you have spotted the commonly known citronella plant, also known as citronella grass, geranium grass, mosquito plant and nard grass. It comes from the plant family Poaceae. The Citronella grass plant is an upright, tufted grass with lanceolate, bluish-green leaves that sprout from long, brownish-red upright stalks and grow to 90-120 cm in length.
Citronella Grass is an aromatic, evergreen perennial native to Sri Lanka but is common in most warm-temperate, subtropical, and tropical regions of Asia and Africa. In cooler climates, citronella is grown as an annual and brought indoors over the winter. It is closely related to lemongrass.
When optimal conditions for growth are met, the citronella weed plant will produce flower spikes on spikelets borne on long flower stalks that extend up to 6 feet from the center of the plant. These buds will self-seed easily, but require constant temperatures of between 20 and 22°C to germinate. The seeds are light brown, dry and typical of grasses/cereals. Plants grown in cooler climates are less likely to produce viable buds.
Plants spread naturally by creeping underground rhizomes and in their native tropical climates with vigorous growth habit can become somewhat invasive and outgrow existing flora and crops.
Citronella grass is typically grown for its insect repellent properties. Many gardeners believe that the citrus aroma of plants is enough to repel mosquitoes, but unfortunately this is not true. It is the citronella oil contained in the leaves that is used in mosquito repellents, but it must first be extracted through the process of distillation. Simply crushing the leaves with your hand will release some oil, but not enough to repel mosquitoes. Nonetheless, some gardeners swear that crushing and rubbing the leaves against their skin is one of the natural ways to apply a mosquito repellent, and this scent can be successful in keeping a few mosquitoes away while you're gardening!
The extracted essential oil has a strong lemon scent that is commonly used to perfume cosmetics, soaps, deodorants and skin lotions specifically used as mosquito repellents. Citronella candles and oil burners are used at night as mosquito repellent. The antibacterial and antifungal properties of the oil make it perfect for cleaning and disinfecting products. Caution should be exercised when using these products. Inhaling the oil fumes can cause allergic reactions in some people, and citronella oil can also irritate sensitive skin. The citronella plant is not edible, unlike its close cousin Cymbopogon citratus, commonly known as lemongrass.
If you bought a "citronella plant" with delicate leaves and a citrus scent, then you most likely have a lemon-scented geranium, sometimes called a citronella geranium. They smell similar to citronella grass, but the leaves do not contain the insect-repellent citronella oil and are therefore ineffective at deterring those pesky mosquitoes from biting. Unfortunately, members of the geranium family, among other flowers, make beautiful plants for your garden, but they just don't repel mosquitoes well!
Plant citronella plant
Citronella can be planted year round when grown in tropical, subtropical, or warm temperate climates. As a vigorous grower, it won't take long for mosquito plants to become established. In cooler climates, wait until late spring to early summer before planting them in the garden.
Choose a spot in full sun with some partial shade during the hottest part of the day. Leaves can burn easily and look unsightly. Citronella grass is adaptable to most soil types, but the mosquito plant prefers moist, clay soil that drains well.
Growing mosquito plants from seed is not recommended as germination can be erratic. Vigorous growth and rhizomatic roots make it a prime candidate for propagation by division.
Citronella grass is perfect for growing as a container plant as it allows you to move plants to a variety of locations to suit your needs. You may need to invest in larger pots if your indoor plants outgrow smaller containers, or simply divide the plant and transplant one division into the same container and share the others with other gardeners. Container growing is a good option for colder zones, as your plant can easily be brought indoors over the winter to protect it from frost.
The base of the citronella plant. Source: Ahmad Fuad Morad
Citronella grass is native to the tropics. However, it is very adaptable to cooler climates if you know how to care for it. Let's talk about the plant, information you need to know to care for it, and how to care for its beautiful foliage in your garden!
sun and temperature
Citronella is primarily a subtropical weed with a preference for full sun (at least six hours) and warm temperatures. In very hot climates, provide shade or filtered sunlight during the hottest part of the day to prevent the leaves from scorching, make sure it gets at least six hours of sunlight.
Don't let this plant's tropical origins stop you from growing it if you're north of the equator! The citronella plant is hardy in USDA zones 10-12 and can tolerate temperatures down to 0 °C (32 °F) but cannot tolerate prolonged periods of frost. Bring your citronella weed indoors in large pots when the first frosts arrive.
water and moisture
Provide long, deep drinks when the soil begins to dry out, or provide drip/drip hose irrigation to maintain constant moisture. Citronella grass prefers consistently moist soil, but surprisingly can tolerate long periods of drought. Reduce watering during the winter months, but check regularly to make sure plants have not dried out completely, especially those grown in containers. A drip hose or other form of drip irrigation at the base of the plant can be used to help water your garden.
For best results, grow citronella in a rich, clay-based, free-draining soil or compost. Citronella grass is very adaptable to most soil types and will do well once established. If the soils are very poor, dig in some organic matter before planting to provide nutrients and help retain moisture. The pH of the soil should be neutral.
Fertilize citronella grass once a year in spring with a high-quality, long-term nitrogen-rich fertilizer. If your plant is looking a little lackluster, a quick fertilizing with a liquid nitrogen fertilizer should get it back to healthy growth habits. Instead of fertilizers, you can also add a top inch of compost around the base of your plant once or twice a year.
Citronella plants require little or no pruning when grown in their natural environment. Perhaps the most they can benefit from is odd pruning of brown leaves and dieback to prevent self-seeding. Plants grown in containers in cooler climates will benefit from a hard pruning to 6 inches (15 cm) above the crown before moving to a sheltered area or indoors over the winter. New shoots will appear in spring, ready to go outside again.
Citronella grass is unlikely to develop viable seeds unless grown under optimal climate conditions. Even with viable seeds, germination is erratic. The main form of propagation for citronella plants is division. The vigorous growing nature of citronella grass lends itself perfectly to division to keep plant size under control. It's also a great way to keep plants in check in containers.
Divide plants that are at least 2-3 years old and have developed a good root system. Dig up the entire plant and divide the plant into as many parts as you need with a saw, spade or knife. Pot each division individually or transplant to new spots in the garden. Water well until plants are established. Using this method ensures that the new mosquito plants have enough time to become well established before the first frost.
Root cuttings are another option if you don't want to dig up an entire plant. Root cuttings should be taken in winter, when the plants are dormant and their roots are nutrient rich, to allow the cuttings to develop best. Simply remove soil from the base of the plant until the roots are visible and use clean scissors to snip off 2-3 inches of the root. Place the cutting in a pot of compost and place in a light and warm spot, keeping the compost moist. Shoots should appear in early spring.
Citronella geranium is not the same as the citronella plant. Source: Starr
Citronella is a low-maintenance plant with few growth problems. Here are a few things to watch out for, just in case.
Your mosquito plant will benefit from afternoon shade to protect the leaves from it sunburn during the hottest part of the day. The burned leaves are unsightly and the damage reduces the plant's ability to photosynthesize, affecting the plant's overall health.
Wet feet can also be a problem for citronella plants. Although they prefer consistently moist soil, heavily wet soil reduces the plant's ability to absorb nutrients from the soil and leads to plant deterioration. It can even cause root rot and death of the plant. Grow citronella grass in free-draining, loamy soil to avoid this growth problem.
Citronella grass tends not to be attacked by pests.
Commercially grown citronella weed can be affected leaf rot. This is especially prevalent in subtropical climates where plants are grown densely to produce citronella oil. Lack of air circulation provides perfect conditions for the spread of putrefaction, leading to a reduction in both the quantity and quality of the extracted oil. Rot is less common in home gardens unless the plants are allowed to become very clogged. Signs of rot are dark spots or lesions on leaves, from which necrosis begins to rot the leaves. Remove and destroy affected leaves immediately. Divide clogged plants every few years and remove dead or dying foliage to improve air circulation. Copper fungicides can be useful to prevent rot.
frequently asked Questions
Mission grass in the foreground, citronella grass blossoms in the right background. Source: Dinesh Valke
Q: Do citronella plants really keep mosquitoes away?
A: The oil extracted from the leaves of citronella plants has some mosquito repellent properties when used in candles, lotions and oil burners. The plants in their natural form do not help repel mosquitoes.
Q: Does citronella plant like sun or shade?
A: The citronella plant likes to grow in a bright, sunny spot, but will benefit from some shade during the hottest part of the day to protect the leaves from scorching.
Q: Is citronella a good houseplant?
A: Citronella is often confused with the citronella geranium or scented geraniums (Pelargonium citrosum), which have a lemony scent and make excellent houseplants. Unfortunately, the citronella geranium does not repel mosquitoes. True citronella plants are large grasses, growing up to 6 feet tall and 4 feet wide, and are very long unsuitable for most indoor spaces. It is an excellent patio plant as most people have enough space on their patio for a larger species.
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