Last Updated on October 31, 2021 by Phil
Citronella Geranium is mostly popularly known as the Mosquito Plant due to the belief that it wards off these insects because of its fragrance. Unfortunately, that’s just a myth. I’ll talk more about it below.
Another name you may hear is Scented Geranium, which comes from its aroma.
The plant is a perennial herb that emits a strong fresh lemony scent when touched. It belongs to the Geraniaceae family.
It is Different from a True Citronella Plant
While they both carry the citronella name, don’t confuse the Citronella Geranium with the true citronella which is a grass (Cymbopogon nardus or Cymbopogon winterianus).
As such, the easiest way to tell the difference is to look at them.
If you’re seeing foliage instead of grass, you’re likely getting the citronella plant which often refers to the Citronella Geranium.
If you’re seeing grass, then that’s your true citronella, which by the way repels mosquitoes.
Citronella Geranium Does Note Repel Mosquitoes
As a follow up, it is likewise important to note that Citronella Geranium do not repel mosquitoes.
Yes, they do emit similar odors. Unfortunately, the scent they produce seems to be different, probably chemically, from that of citronella grass. As such, it is not effective in keeping mosquitoes away.
That said, if you do enjoy the aroma, you can use the plant as well.
However, do know that it produces it fragrance when touched. So, it is best to treat it like some herbs were you crush them and rub that on skin or place that in a container.
Citronella Geranium are bushy shrubs that produce multi-colored flowers between April and October. But for the most part they are known for their unique shaped foliage.
They grow up to 6 feet tall and about 3 feet wide.
You’ll often find them in containers, patios and walkways. They’re likewise amazing for borders, and window boxes.
Because of their fragrance, people use them as potpourri.
Citronella Geranium Plant Care
Citronella Geranium Light Requirements
Citronella Geranium can be grown indoors and outside. As always, it is always good to keep in mind that the there’s more light outside than inside.
As such, bright light indoors can sometimes be equivalent to something like bright shade outdoors. That’s because of ceilings and walls in your home block out majority of the sun.
And, the only openings where the sun is able to get in are windows. Of course, there are exceptions. For example if you have an entire wall of windows on one side of the house. Or, if you have a solarium or sun room where the roof is made from glass as well as most of the walls.
As such, if a plant needs a lot of light, it will likely need more of it indoors. Inversely, if a plant needs to be kept from direct sunlight, you’ll need to protect it more outdoors.
When it comes to the Citronella Geranium, full sun is ideal. It needs at least 6 hours of sunlight daily. Although, it can tolerate partial shade.
Similarly, keeping it away from direct sun or too much bright light during the hottest times of the day is important.
This means indoors, it does best in the south, west and east facing windows. There’s less precaution needed with an eastern exposure because the sun is not at intense.
In the west and south, you want to protect it or distance it from too much afternoon sun.
Outdoors, it will likewise appreciate full sun especially if you live in the cooler regions of the country. You do want to be a little bit more cautious about hot afternoon sun. During this time, it is a good idea to keep them in bright shade.
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Scented Geranium Temperature
Citronella Geranium are hardy to USDA zones 9 to 11. It prefers warm weather. And, if you live in these areas, you’ll be able to grow them in your garden without the threat of winter.
Otherwise, make sure to bring the indoors before first frost.
The plants are not frost hardy. As such, they will not survive snowy winters.
However, they can tolerated conditions down to 30 and 40 degrees Fahrenheit. Note that this is just for survival purposes. By the time the climate gets this low, they’ve sustained quite a big of damage already.
So, ideally, you want to transfer them indoors before temperatures drop under 50 degrees.
Ideally, keeping things between 60 and 70 degrees Fahrenheit will allow the plant to grow at its best and produce the most flowers.
This makes it easy to grow indoors since we’re most comfortable around these temperatures as well.
Mosquito Plant Humidity
Citronella Geranium enjoy humid environments. The thrive when relative humidity is kept between 40% and 70%.
This means is may or may not be a problem for your home depending on where you live. Most U.S. homes average between 40% and 505 humidity. But, during winter, this number drops to between 30% and 40% because the air gets drying with the cold weather.
As such, if this happens, you’ll need to apply some measures to increase humidity in your home. This can including regular misting, keeping them in the bathroom or placing it over a pebble tray.
Obviously, you have less control over humidity levels outdoors.
How Often to Water Scented Geranium
Citronella Geranium need consistent evenly most soil. This means regular watering, especially in the summer.
But, you do want to avoid overwatering, soggy or wet soil. All of these conditions are bad for the plant. And, if it stays in these conditions for longer periods of time on a regular basis, sooner rather than later it will experience root rot.
As such, when grown in containers, you want to allow the top layer of soil to dry before watering again. Once the top 1 to 2 inches go dry, it is time to water before that. But, not before.
Outdoors, the plant is drought tolerant. This means you can grow it in xeriscapes or rock gardens. Similarly, if your locale is fairly dry or doesn’t get a lot of rain, it will be find in the garden.
Similarly, your Citronella Geranium does not have a problem with hot summers. But, you do want to keep it away from the brunt of the intense sun during this time.
Interestingly, dryness has a hidden benefit. While it does turn foliage yellow, it also increases flowering. As such, you’ll need to experiment to find the right balance for the home or garden environment you have.
Ideally, water in the morning. This allows the plants to absorb most of the water as opposed to the afternoons where evaporation can compete with it due to the warm sun.
At the same time it also gives the moisture enough time to dry. Thus preventing root rot and other fungal problems.
The worst time to water is during later afternoon or evenings when the moisture can stay overnight and cause problems in the long run.
Soil for Citronella Geranium
Citronella Geranium is not choosy about soil. As long as the soil is well-draining it will grow well.
However, if you want optimum growth, moist fertile soil is best. Keeping soil pH between 6.0 and 7.0 likewise helps.
Because it is not fussy about soil, it is easy to grow in different places, as long as the weather is right.
If you grow it in the ground, make sure to give it between 18 to 24 inches of space between plants. Good companion plants that will help it thrive include coleus, nasturtium, thyme and mint.
If your yard does not have good soil, you can improve it by adding a few inches of compost as well as other sources of rich organic matter.
Just as importantly keep it under partial shade so as not to get too much intense sun.
Mosquito Plant Fertilizer
Citronella Geranium may or may not need feeding depending on where you grow it.
In the garden, if you have rich or loamy soil, it won’t need fertilizer.
Alternatively, you can also add a couple inches of so of compost or mulch to improve the soil. Compost contains high amounts of organic matter. Meanwhile, when mulch breaks down, it releases nutrients to improve the soil as well.
In containers, you’ll likely be using potting mix, which is soilless. As such, you’ll need to supplement the nutrients yourself. Here’s where you’ll need to feed the plant.
Use a balanced liquid fertilizer once a month during the growing season. Make sure to dilute it to half the recommended strength.
When applying fertilizer, make sure not to overdo it. Too much plant food is more harmful than not providing enough. That’s because it will result it fertilizer burn that will damage the plant’s roots and leaves.
Pruning Mosquito Plant
Citronella Geranium grow up to 2 to 4 feet tall. Depending on where you grow it, you may want to trim it to limit is size and shape.
More importantly, regular light pruning allows the plant to become bushier. This makes it look its best. That’s because pruning and pinching will encourage new foliage growth.
Similarly, remove spent flowers which bloom during the summer.
Citronella Geranium can also be prone to leggy stems if they don’t receive enough light. The plant will try to reach out and grow toward the light source, in the process becoming long and thin.
This is not a good look for it. And, you want to prune these lanky stems to fix the problem.
Citronella Geranium Propagation
Citronella Geranium can be propagated from cuttings and seeds. This will allow you to grow more of the plant from what you already have.
The best times to do this is during spring or early summer. Although you can technically do them any time of the year, doing in early in its growing season allows the new plant to quickly develop.
How to Propagate Scented Geranium from Cuttings
- Starting by taking cuttings from soft wood or herbaceous growth. You want to choose healthy stems with at least 2 or 3 leaves on it.
- Dip the end of the cutting with rooting hormone powder.
- Place the cutting (powder end) into a small container with moist, sandy soil. You will want to keep the soil moist without overwatering it.
- Cover the plant with a plastic bag to increase humidity. If you have a humid spot for it, you won’t need to use the plastic bag.
- In about 3 to 4 weeks, the cutting will have developed some roots.
- Allow it to continue to grow till about week 6. Then, you can move it to a larger container or plant it in the garden.
How to Propagate Scented Geranium from Seeds
- Start the seeds late in the summer or early in the fall.
- Place the seeds in a light, well-draining potting mix. Spread them around the soil on the try to distribute evenly.
- Lightly water to keep them moist (use a spray).
- Place them in a bright place with no direct sunlight exposure.
- The seeds will take 2 to 3 weeks to germinate.
Overwintering Mosquito Plant
The plant is hardy to USDA zones 9 to 11. If you live in these areas, you can keep it outside all year long. However, in areas where winters experience frost, the plant is grown as an annual.
Your other options are either to grow it as a houseplant or keep in in container so you can take it indoors once the cold weather comes around.
One way to overwinter the plant is to propagate it via layering during the summer. This will let you have a new growing plant to bring indoors come winter.
- Place a pot with fresh potting mix beside your Citronella Geranium.
- Take one of its stems and bend it over to the pot. You want to get longer one so it can easily reach. Be careful not to break the stem. You want them stem to stay connected with the mother plant.
- Burn part of the stem horizontally where so that the spot where a leaf attaches to the stem stays under the soil. But, keep the tip out of the soil.
- Use a stone or other weighted object to keep the stem under the soil. Don’t use anything too heavy or too light.
- After several weeks, new roots will emerge from the stem growing down into the potting mix.
- Allow it to keep growing.
- Before first frost arrives, cut the stem to separate the new plant from the mother plant.
- Now you have a new propagated young plant to take inside to grow through the winter. You can then take it outside once spring arrives.
How to Plant, Transplant and Repot Mosquito Plant
How you plant your mosquito plant will depend on whether you want to grow them in containers or in the ground.
Planting Scented Geranium in Containers or Repotting Them
Citronella Geranium are fast growers. As such, you will likely need to repot them more than other Pelargoniums.
If you’ve just gotten them from the nursery, it will often come in a bag or pot. Remove the packaging and any other material that may come with it.
Check the plant for any problems. This includes yellow or brown leaves. Remove these as well as fasded blooms if there are any.
Now for repotting.
- You will need a container that’s about 12 to 14 inches wide in diameter. If the plant is much smaller, pick a container that’s 2 inches wider than the one that it is currently in.
- Make sure the new pot has a drainage hole at the bottom to allow excess moisture to escape.
- Add fresh potting soil that is well draining into the new container.
- Take the plant out of its existing pot.
- Brush off any excess soil and dirt from the root ball.
- Then, insert the plant into the new pot.
- Backfill the extra spaces with fresh potting mix.
You can keep the plant indoors or place them outside. If you decide on the latter, make sure that the temperature is 50 degrees Fahrenheit or higher. If it falls below that, bring the plant indoors.
Transplanting Mosquito Plant into the Ground/Soil
- If you’re transplanting your Citronella Geranium into the garden, follow these steps.
- Wait until the risk of frost has passed and the soil has warmed up. You don’t want to put the plant into the freezing ground.
- Pick a location where it will receive full sun (6 or more hours daily). Ideally, the spot should get some shade from the harsh afternoon sun.
- Keep plants spaced out 18 to 24 inches apart. This will give their roots enough space to spread.
- Ideally, you want to plant a young mosquito plant. That’s because they’re stronger and more vigorous.
- If you can help it, use fertile, moist soil. Although, the Scented Geranium will do okay with almost any kind of soil as long as it is well draining.
- Place the mosquito plant into the hole you dug up.
- Add 3 inches of compost to the top 6 inches of soil.
- Feed regularly during growing season.
According to the ASPCA, Citronella Geranium is toxic to dogs and cats. As such, it should not be ingested. It can result in gastrointestinal problems and cause vomiting.
Similarly, keep young children away from the plant as they may get tempted to play and chew on it.
Pests and Diseases
Mosquito plants are practically disease free. This makes them so much easier to care for since you have one less potential problem to worry about.
Pests are another issue. While mosquito plants can resist pets when healthy, they can still experience attacks from these creatures.
The most common invaders including whiteflies, aphids, mealy bugs and caterpillars.
In most cases, using insecticidal soap or dishwashing soap with water will get the job done. You can also use neem oil.