Acclaimed for its distinctive citrus scent, the much-lauded Citronella plant, scientifically known as the Citronella Geranium, is a popular addition to many gardens.
Native to South Africa, it’s a member of the geranium family that has built a sterling reputation as a natural mosquito repellent. It’s further adulated for its vibrant leaf nodes and stems, providing an attractive contrast to its bloom of beautiful, pastel-colored geraniums that flower in cooler climates.
The Citronella plant, or Citrosum, generates a charming fragrance from its leaf, hypnotizing plant lovers, while simultaneously acting as an invincible shield against mosquitoes and other pests.
Though this mosquito plant doesn’t produce citronella oil like lemongrass or citronella grass does, its scent closely mimics it. Thus making it an exceptional mosquito deterrent and a delightful patio decor.
Supplementing your garden with this plant not only adds a touch of tropical ambiance to your landscape but further helps create a mosquito-free environment, an attribute that has propelled the popularity of these plants to new heights.
As a master gardener, I get asked a lot about this incredible plant. And so, in this article, I’ve come up with a complete guide to growing and caring for citronella plant.
Photo Credit: Shutterstock.
Botanical Name: Pelargonium citrosum
Common Name: Citronella Plant, Mosquito Plant
Family: Geraniaceae
Plant Type: Herbaceous perennial
Hardiness Zones: 10 – 11 (USDA)
Sun Exposure: Full to partial sun
Soil Type: Well-drained sandy loam
Soil pH: 5.8 – 6.3
Bloom Time: Summer
Flower Color: Pink, purple
Native Area: South Africa
Citronella Plant Care
For those battling with mosquitoes, you’ll find the Citronella plant, also known as Citrosum or Mosquito plant, to be a natural mosquito repellent due to its strong citrus scent.
It prefers a full sun but benefits from a bit of afternoon shade, especially in hotter climates. Make sure you place these plants in pots on your patio where they can receive six hours of sunlight each day.
Ensure top inch of soil is dry before watering to prevent issues such as root rot from overwatering. They thrive in high moisture but require good drainage.
When the temperature drops, ensure to bring them inside before the first frost to promote new growth.
Photo Credit: Shutterstock.
Light
Citronella plants thrive under full sun to partial shade conditions. Ideally, these plants enjoy a location that receives at least six hours of sunlight daily, yet also offers some afternoon shade, particularly in hotter climates.
Regions like South Africa, where the sun is more intense, can result in leaf burn if the plants are exposed to direct sunlight all day. Consequently, morning sun and evening shade tend to be the most optimal environment.
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In cooler climate regions, citronella plants can tolerate all-day sun exposure, fueling the energy they require for new growth.
Soil
Citronella plants prefer well-draining soil conditions. Overwatering these plants can lead to root rot, a common issue faced by gardeners. The top inch of soil needs to dry out before the next watering for ideal growth conditions.
Waterlogged soils can inhibit the growth of new stems and lead to an overall unhealthy plant. Citronella plants also love rich, organic materials in their soil.
These materials can be achieved through compost or a high-quality potting mix. If growing in pots, be sure the pot has sufficient drainage holes to avoid water stagnation.
Water
When it comes to watering citronella plants, a balanced approach is required. These beautiful members of the geranium family thrive in moisture, but are prone to root rot if they are subjected to overwatering.
The ideal method involves watering the plant until the top inch of soil is moist, then allowing the soil to dry before the next watering. In cooler climates or when grown in pots indoors, citronella plants should be watered less frequently.
Remember, a citronella plant struggling due to dry conditions can recover, but excessive watering can lead to irreparable root rot.
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Following these tips will not only keep your citronella plant healthy, but it will also encourage the production of its new growth with that distinctive citrus scent.
Temperature and Humidity
Citronella plants thrive best in cooler climates with moderate humidity. A member of the geranium family, these citrosum species prefer temperatures between 15°C to 21°C (60°F to 70°F).
They originate from South Africa, and thus can be sensitive to freezing temperatures. The plant should be carefully sheltered or brought indoors before the first frost hits.
In terms of humidity, a well-drained pot in full sun or partial shade, ensuring proper afternoon shade, can stave off most pests and excessive moisture issues.
Fertilizer
When nurturing this plant, you must remember that overfertilization can lead to abundant leaf growth, but fewer blooms.
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This South African plant requires a balanced, water-soluble fertilizer with equal amounts of nitrogen, phosphorus, and potassium. It’s best to fertilize every two weeks during the growing season for optimum growth.
If the plant is in a pot, ensure to wash out the top inch of soil every few months to rid it of excessive salts derived from rigorous fertilization.
Pruning
Maintaining the optimal growth and health of your citronella plants involves regular pruning.
Focus primarily on dead or dying leaves and stems, making sure to slice at leaf nodes to encourage new growth. This not only enhances the citrus scent of your Citronella Geranium but it also fosters a blooming, healthy appearance that enlivens any patio or pot arrangement.
Pruning should be done just before the first frost in cooler climates to keep the plant robust and ready for the next growing season.
Always remember, proper pruning indirectly benefits the effectiveness of your plant as a mosquito repellent as healthier plants generally release stronger scents that keep pests like mosquitoes away.
Don’t hesitate to remove the top inch of soil around the plant when pruning, it aids in the prevention of diseases like root rot which can occur due to overwatering.
Overwintering
Citronella plants, which are actually scented geraniums, thrive outdoors in the full sun during summer but need to be overwintered indoors in areas with harsh winters.
Move your citronella plants inside before the first frost, ensuring you place them in a location that gets several hours of sunlight each day. The ideal indoor environment should mimic the plant’s native South Africa: warm with a lot of sunlight.
Despite the switch in location, continue watering, allowing the top inch of soil to dry out before rehydrating to avoid root rot caused by overwatering. Trim back any new growth to keep the plants compact and promote thicker leaf growth in the spring.
Remember, even though they prefer a cooler climate during winter, the afternoon shade may not be enough for these sun-loving beauties.
How to Plant Citronella Plant From Seed
Choosing the Right Environment
Citronella plants prefer full sun or partial shade. They need at least six hours of sunlight each day to flourish. This plant prefers a cooler climate, and an afternoon shade will provide it respite from the intense heat.
Having the pot in a patio could also be an ideal location because Citronella geraniums appreciate the warmth radiating from the patio stones.
Photo Credit: Dreamstime.
Selecting the Correct Pot
Choose a pot with ample drainage since overwatering can lead to root rot. Moisture is essential for geraniums, but too much could damage the plant. To check if your plant needs water, dig your finger into the top inch of soil. If it’s dry, it’s time to water.
Planting the Seed
Place the citrosum seed onto a bed of soil and cover lightly with a sprinkle of additional soil. Warmth will stimulate germination, so place your citronella plant pot in a warm, sunny spot. After a couple of weeks, you should begin to see new growth.
Caring for Your Plant
Caring for a Citronella Geranium involves pruning it back, especially at the end of winter. Look for the leaf nodes along the stems as these will stimulate new growth when cut back to just above these points. Regular pruning will keep the plant bushy and productive.
How to Propagate Citronella Plant
Step 1: Selecting The Plant
Start with a healthy citronella plant. Ensure the plant has green, insects-free leaves, and well-established stems. Preferably, choose the plant during its bloom period, usually the warmer months, so you can see the flowers and get a sense of the scent.
Step 2: Cutting and Preparing Stems
Snap a stem just below a leaf node. The stem should be healthy, around 3-6 inches long, with several leaf nodes.
Make sure your chosen stem is free from pests and diseases. Remove all the leaves from the bottom half of the stem, as these will be submerged in the water or soil and can cause rot.
Photo Credit: Shutterstock.
Step 3: Choosing Your Propagation Method
Citronella can be propagated by either root cutting or direct soil potting. If you prefer direct potting, stick the bottom half of your stem cutting into a pot with well-drained, moist soil.
If using the water method, simply place the cuttings in a vase or glass of water, ensuring the top inch of soil is not submerged.
Step 4: Providing Proper Care
Citronella is partial to full sun and requires at least six hours of sunlight each day, although a little afternoon shade can be beneficial in high-temperature climates.
Whether you chose to plant in pots or directly in the ground, provide enough moisture without overwatering to avoid root rot. Be cautious – cooler climates or the first frost can be fatal to new growth.
Step 5: Repositioning the Plant
Once you see a good root formation, transfer the plant to its final location. If you are adding to a patio pot or container garden, ensure the pot is large enough for the plant to grow.
How to Pot or Repot a Citronella Plant
Step 1: Selecting the Pot
Citronella plants have strong stems and need room to grow and bloom. Choose good-sized pots with room to support new growth.
These pots should have drainage to prevent root rot caused by overwatering. Fill your pots with enough soil, leaving the top inch of soil empty.
Step 2: Planting Time
This plant loves a healthy dose of full sun to partial shade. At least six hours of sunlight is ideal with some afternoon shade for a cooler climate. Arrange the plant in your pot so the leaf nodes are just above the soil surface.
Photo Credit: Shutterstock.
Step 3: Proper Care
Watering this plant requires a delicate balance – too much moisture and the plant risks root rot; too little and it will wither and die.
The top inch of soil should dry out between watering to avoid overwatering, and the plant should be moved indoors before the first frost to protect it from cold climates.
Step 4: Repelling Insects
Citronella plants are great as natural mosquito repellants. The scent of citronella can deter mosquitoes as well as other insects from your patio or garden.
Moreover, essential oil from citronella, lemongrass, lavender, and catnip can be used as mosquito repellent.
Common Pests and Plant Diseases for Citronella Plant
Mosquitoes, pests, and insects are known to cause a nuisance in most gardens, but the scent of citronella plants often repels them. Yet, even these scented Germaniums can fall prey to certain pests and diseases.
Aphids
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Aphids are tiny insects that feed on the succulent new growth of plants, potentially causing curled and discolored leaves.
Although these pests are generally repelled by the citrus scent, large infestations can occur on Citronella Geranium. Using a mild insecticide or ladybug predators can mitigate this problem.
Overwatering and Root Rot
Overwatering the Citronella plant can lead to the dreaded root rot. This cools the plant’s climate and typically manifests as yellowed, wilting leaves.
To prevent this, ensure only the top inch of soil in the pot is kept moist, and the plant is kept in afternoon shade or partial shade.
Spider Mites
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Spider mites, microscopic arachnids, attack the underside of leaves on citronella plants, causing them to turn yellow and drop off.
These mites thrive in full sun, especially if the plant lacks adequate moisture. Frequent misting and introducing natural predators like ladybugs can help maintain healthy plants.
Common Plant Problems and Solutions for Citronella Plant
Brown Tips
Brown tips on the leaves of citronella plants are a common issue, often resulting from overwatering. Too much moisture can lead to root rot, a grave condition for your Citronella Geranium.
Check the top inch of soil for dryness before watering and ensure your plants in pots have proper drainage to prevent standing water.
Yellowing Leaves
If your citronella plant’s leaves are yellowing, it could be receiving too much full sun. While these geranium family members enjoy at least six hours of sunlight, they thrive best in a combination of full sun and afternoon shade.
If the yellowing continues, consider moving the plant to a cooler climate on your patio where it can get partial shade.
Leaf Drop
Leaf drop or new growth appearing to be suppressed can be a sign that your plant isn’t getting enough light. Citronella plants are native to South Africa; hence, they thrive in bright environments.
Move your plant to a location where it can get at least six hours of sunlight for optimal growth.
Fading Scent
Photo Credit: Dreamstime.
Citronella plants are known for their strong citrus scent, a natural mosquito repellent. If the fragrance begin to fade, it may be due to a lack of essential nutrients.
Regular feeding with a water-soluble fertilizer can help maintain the plant’s vigorous growth and robust scent.
The citrosum, or scented geranium, is particularly known for its potent fragrance, which makes it a great mosquito deterrent.
After First Frost
As a warm-weather plant, citronella does not handle frost well. If your plant turns black after the first frost, trim the stems back to the leaf nodes to encourage new growth in the spring.
If you live in a cooler climate, consider growing your citronella in pots, so they can be easily moved indoors during the colder months.
Other Plant Guides from Planet Natural:
How to Grow and Care for Century Plant (Agave americana)
How to Grow & Care for Aglaonema Plants (Chinese Evergreen)
Melissa Pino is a biologist, master gardener, and regular contributor for Planet Natural. Melissa's work focuses on promoting environmentally-friendly practices, helping people create healthy gardens and finding ways to achieve overall health and wellness.
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