When planning a garden or looking for natural solutions, you might find yourself comparing citronella plant vs lemongrass. While both citronella plant and lemongrass contain citronella oil, they are different species with unique growth habits and uses. This confusion is common, and choosing the right one depends on what you need.
This guide will explain the key differences. You will learn how to identify each plant, care for them, and use them effectively. We cover everything from appearance to pest control properties.
Citronella Plant Vs Lemongrass
Understanding the fundamental distinction is crucial. The “citronella plant” commonly sold for mosquito repellent is actually a scented geranium, while lemongrass is a true grass used in cooking. Their scientific names reveal their seperate families.
Citronella plant refers to Pelargonium citrosum, also called the mosquito plant. It is a member of the geranium family. Lemongrass refers to Cymbopogon citratus, a perennial grass in the Poaceae family. This basic difference affects everything else about them.
Botanical Origins And Classification
Their scientific classifications place them in completely different plant orders. This is the root of their distinct characteristics.
The citronella geranium is a hybrid developed for its strong citronella-like scent. True citronella oil, used in commercial repellents, comes from a different grass species called Cymbopogon nardus or Cymbopogon winterianus. The common garden “citronella plant” is a marketing name that causes much of the confusion.
Lemongrass is a culinary and medicinal herb native to tropical regions of Asia. It’s a key ingredient in many Southeast Asian dishes. Its oil is also harvested for various uses.
Primary Uses And Common Misconceptions
People often buy these plants for specific reasons, but expectations don’t always match reality.
The citronella plant is primarily marketed and purchased as a natural mosquito deterrent. However, its effectiveness is debated. The concentration of repellent oils in its leaves is much lower than in true citronella oil. Simply having the plant in your garden may not repel mosquitoes effectively.
Lemongrass has two main roles:
- Culinary Herb: The tender inner stalks are used to flavor soups, curries, teas, and marinades.
- Source of Oil: Its oil is used in aromatherapy, soaps, and as a fragrance.
A major misconception is that lemongrass and citronella are the same. They are related grasses within the Cymbopogon genus, but the species used for cooking is not the same one used for high-grade repellent oil.
Visual Identification Guide
Once you know what to look for, telling these plants apart is straightforward. Their growth form and leaf structure are very different.
Citronella Plant Appearance
The citronella geranium looks like a typical bushy, mound-forming geranium.
- Growth Habit: It grows as a woody-based, bushy perennial often treated as an annual in colder climates.
- Leaves: The leaves are lacy, deeply serrated, and palmate (shaped like a hand). They are green and release their scent when crushed.
- Flowers: It produces small, lavender or pink flowers that resemble other geranium blooms.
Lemongrass Appearance
Lemongrass looks like a tall, ornamental grass you might see in a landscape.
- Growth Habit: It forms dense, upright clumps of grassy foliage, growing from a bulbous base.
- Leaves: The leaves are long, slender, blade-like, and have sharp edges. They arch gracefully from the base.
- Stalks: The most recognizable part is the thick, fibrous, pale green stalk at the base, which is the part used in cooking.
Growing Requirements And Care
Both plants enjoy warmth and sun, but their specific needs and hardiness vary significantly. Success depends on providing the right conditions.
Climate And Hardiness Zones
Your geographic location will determine how you can grow these plants.
The citronella plant is hardy in USDA zones 9-11. It cannot tolerate frost. In cooler zones, it is grown as an annual or in pots that are brought indoors for winter. Lemongrass is also a tropical plant, thriving in zones 10-11. It is even more sensitive to cold than the citronella geranium and will die back at the first frost.
Sunlight And Temperature Needs
Both are sun-loving plants that originate from warm climates.
- Citronella Plant: Prefers full sun to partial shade. At least 6 hours of direct sun is ideal for robust growth and strong scent production.
- Lemongrass: Requires full sun for optimal growth. The more sun it gets, the faster and larger the clump will become.
Both need warm temperatures. They grow best when daytime temperatures are consistently above 70°F. Protect them from temperatures below 40°F.
Soil, Watering, And Fertilization
Their soil and moisture preferences have some similarities but key differences in tolerance.
Citronella Plant Care:
- Soil: Well-draining potting mix is essential. It does not like “wet feet.” A standard potting soil with some perlite works well.
- Watering: Water when the top inch of soil feels dry. It is moderately drought-tolerant but will suffer if left completely dry for to long.
- Fertilizer: Feed with a balanced, water-soluble fertilizer every 4-6 weeks during the growing season.
Lemongrass Care:
- Soil: Prefers rich, loamy soil that retains moisture but still drains well. It can tolerate heavier soil than the citronella plant.
- Watering: Needs consistent moisture, especially when getting established. It thrives with regular watering and can even grow in somewhat boggy conditions.
- Fertilizer: Benefits from a nitrogen-rich fertilizer to support its vigorous leafy growth. Apply a balanced fertilizer monthly in the growing season.
Propagation Methods
You can expand your collection of both plants through simple techniques.
Citronella Plant Propagation: It is most easily propagated from stem cuttings.
- Take a 4-6 inch cutting from a healthy stem.
- Remove the lower leaves and dip the end in rooting hormone (optional).
- Plant in a pot with moist potting mix.
- Keep in a warm, bright spot until roots develop.
Lemongrass Propagation: It is easily propagated by division or from store-bought stalks.
- To divide, dig up a mature clump in spring and use a sharp shovel or knife to seperate it into smaller sections, each with roots attached.
- To grow from a stalk, place the root end in a glass of water. Change the water every few days until new roots grow, then plant in soil.
Practical Applications And Uses
This is where the plants truly diverge. Their applications in the home, kitchen, and garden are distinct.
Citronella Plant Uses
The uses for the citronella geranium are focused on its aromatic foliage.
- Mosquito Repellent: While its effectiveness as a passive plant is low, crushing the leaves and rubbing the oil on your skin can offer short-term, mild repellency. It’s best used as part of a broader strategy.
- Fragrant Foliage: The leaves can be dried and used in potpourri or sachets to freshen drawers.
- Ornamental Value: It’s an attractive container plant for patios and decks where its scent can be enjoyed up close.
Lemongrass Uses
Lemongrass is incredibly versatile, with both edible and non-edible applications.
Culinary Uses Of Lemongrass
It is a staple in many kitchens. The tender, inner part of the lower stalk is the part you use.
- Flavoring Agent: Adds a bright, lemony, and slightly gingery flavor to soups, curries, and stir-fries. It is often bruised or chopped and then removed before serving, like a bay leaf.
- Teas and Infusions: Fresh or dried lemongrass makes a refreshing and calming herbal tea.
- Marinades and Pastes: It is a key component in many Thai and Vietnamese curry pastes and marinades for meat and fish.
Medicinal And Aromatic Uses
Beyond the kitchen, lemongrass has a long history of use.
- Essential Oil: Lemongrass oil is used in aromatherapy for its invigorating and clarifying scent. It is also a common ingredient in natural cleaning products.
- Traditional Medicine: It has been used to help with digestion, anxiety, and as a mild antiseptic.
- Insect Repellent: The oil, when properly formulated into sprays or candles, can be an effective insect repellent, often more potent than the citronella geranium.
Effectiveness In Mosquito Control
This is a critical point of comparison. Many people choose these plants primarily for pest control, so setting realistic expectations is important.
How Citronella Oil Works
True citronella oil, from Cymbopogon nardus, masks scents that attract mosquitoes and may interfere with their ability to land and bite. It is a contact repellent. The oil from the citronella geranium (Pelargonium citrosum) has similar compounds but in much lower concentrations.
Evaluating The Plants Themselves
Simply placing either plant in your yard will not create a mosquito-free zone. Mosquitoes can easily fly around them.
Citronella Plant (Geranium): Studies have shown that the living plant has little to no effect on repelling mosquitoes. The oil concentration in the leaves is too low to create an effective barrier. Its reputation is largely anecdotal.
Lemongrass: The living plant also does not repel mosquitoes effectively. However, lemongrass oil is sometimes used as an ingredient in formulated repellent sprays and candles. Its effectiveness is better when the oil is extracted and applied directly to skin or burned.
Best Practices For Natural Repellency
If you want to use these plants as part of a mosquito control plan, here are the most effective methods:
- Create a Barrier: Plant multiple lemongrass or citronella geraniums in containers around seating areas. The combined scent may offer a mild deterrent.
- Use the Leaves Directly: Crush the leaves of either plant and rub them on your skin and clothing for a short-term, personal repellent effect. Always do a patch test first to check for skin sensitivity.
- Make a DIY Spray: Steep chopped leaves in boiling water, strain, and mix the cooled liquid with a bit of vodka or witch hazel as a preservative. Use as a spray.
- Eliminate Breeding Grounds: The most effective natural control is removing standing water where mosquitoes breed. No plant can compensate for a yard full of stagnant water.
Frequently Asked Questions
Here are answers to some common questions about citronella plant and lemongrass.
Can I Use Lemongrass And Citronella Plant Interchangeably In Cooking?
No, you cannot. The citronella geranium is not considered edible and should not be consumed. Only lemongrass (Cymbopogon citratus) is safe and intended for culinary use. They have very different flavors and purposes.
Which Plant Is Better For Repelling Mosquitoes?
Neither plant is highly effective at repelling mosquitoes when simply growing in a pot. For actual repellency, commercially formulated products containing high concentrations of true citronella or lemongrass oil are more reliable. Between the two, lemongrass oil is more commonly used in effective natural repellent recipes.
Can I Grow Citronella Plant And Lemongrass Indoors?
Yes, both can be grown indoors with sufficient light. They need a very sunny south-facing window or supplemental grow lights. Lemongrass requires more space due to its large, clumping growth habit. The citronella plant is often more suited to indoor container life.
Are These Plants Toxic To Pets?
The ASPCA lists lemongrass as toxic to dogs and cats, potentially causing stomach upset. The citronella geranium (in the Pelargonium family) is also considered mildly toxic to pets if ingested in large quantities. It’s best to keep both plants out of reach of curious pets.
How Do I Overwinter These Plants In Cold Climates?
For the citronella plant, bring potted plants indoors before the first frost. Place them in a sunny spot and reduce watering. For lemongrass, you have two options: dig up a small clump, pot it, and bring it indoors as a houseplant, or harvest the entire plant in the fall. You can also take divisions in late summer to pot and bring inside.