QUESTION: Can you grow citronella plants indoors? I’ve been keeping some in my outdoor garden, but I’d like to try raising one as a houseplant.— Paul C.
ANSWER: Yes, citronella plants do quite well indoors. We’ve got everything you need to know about keeping a citronella plant as a houseplant. Ready to find out how to raise citronella plants indoors? Let’s get started.
More than one plant out there has the moniker of “citronella plant,” so let’s take a moment to clear up any confusion about the two different plants. This article is about the citronella geranium, Pelargonium citrosum. The information in this article does not apply to citronella grass plant, Cymbopogon nardus. If you’d like to learn more about the two different citronella plants, you can check out our article Citronella Plant Vs. Citronella Grass.
Growing citronella plants indoors is the best way to enjoy them year-round and keep them as part of your collection for years to come. Citronella plants are not frost hardy, so in most zones where they are kept outdoors, they are grown as an annual. (Citronella plants can only be kept outdoors year-round in specific zones 9 through 11.) That means most gardeners will need to either raise their citronella plants indoors or bring them inside in the winter months if they want to enjoy their citronella plants on a long-term basis.
When you brush the leaves of the citronella plant with your fingers, the plant emits a citrusy aroma, citronella oil, that is a natural product known for repelling annoying mosquitoes. However, gardeners don’t only enjoy these plants for their scent and their use as natural mosquito repellents. Citronella plants are also beautiful a flower bed, with lacy leaves and pretty blossoms tinged with pink, purple, or red. The blooms even make an unexpected addition to cut flower arrangements.
How to Plant Citronella Plants Indoors
First, you’ll need to choose a container that’s the right size for your citronella plant. The container should be at least twice the width of the plant’s root system. As a rule, as a good starting point you should use a larger pot that’s at least 12 inches wide by 12 inches deep.
It’s important that your citronella plants are provided with soil that drains well. For best results, the containers you grow your citronella plants in must have drainage holes in the bottom. MacGyver solutions like broken pottery or rocks in the bottom of the container are not an effective way of helping with drainage, so the holes are important. Use a loose, rich soil or potting mix.
If you’re planting citronella outdoors but you know your citronella plants are destined to move indoors at some point, you may wish to consider planting your citronella plants in containers. That way, once it’s time to move them indoors, you simply pick up the pot and move it to its new location. You won’t need to fuss with digging up plants or finding containers to move them into.
When to Move Outdoor Citronella Plants Inside
If you’ve been growing your citronella plants outside, unless you’re in zones 9 through 11, you’ll need to bring them indoors if you want them to survive the winter. But how do you know when to bring your citronella plants inside? Just keep track of the temperature. Citronella plants thrive when the temperature is between 59 and 69 degrees Fahrenheit (15 to 20.6 degrees Celsius). That means once the temperature starts to dip below the 59-degree mark, it’s time to move your citronella plants indoors for the winter. You can bring them outside again in early spring, when the cold weather passes.
However, you don’t want to jerk your citronella plants from the luxury and temperate climate of indoor living to the great outdoors, with its beating sun and harsh winds. You’ll want to use hardening off—a process that gets plants gradually reacquainted with being outdoors so that problems like sunscald are avoided.
Start by introducing a few hours in a protected spot, like a patio or a place tucked under an awning or between buildings. Then you can move the plants to a more exposed area. Each day, leave the citronella plants outdoors for a little longer, like an hour or two, until they’re spending the whole day outside. Then they’re ready to be left outdoors all day long.
How to Propagate Indoor Citronella Plants
It’s easy to take new cuttings from an outdoor citronella plant using the layering technique to bring indoors for a container garden.
Start by preparing a container just as you would for growing citronella plants indoors. Place your container next to the outdoor citronella plant.
Gently bend a long stem from the outdoor citronella plant over to the nearby container, being careful not to break the stem. Bury the stem, making sure to get a node (where a leaf is growing) underground. You can use a rock or a landscape staple if you need it to keep the stem in place.
The node that is currently producing the leaf is where the roots of the new citronella plant will grow. Leave the tip of the stem that is still growing above the surface of the soil. It’s important to have evenly moist soil.
It will take a few weeks for the new plants to put down roots in the container. (So you’ll want to start this process at least a few weeks before the first forecasted frost in your area.) Once the buried stems have put down roots, you can cut them from the outdoor plant and move the newly propagated citronella plant indoors.
Tips for Growing Citronella Plants Indoors
- Find a spot for your indoor citronella plant that gets plenty of direct sunshine. Your indoor citronella plants need at least six hours of direct sunlight each day to thrive. If you do not have a spot for your citronella plant that provides full sun, the plants will tolerate partial shade but will just not perform as well. The sunshine helps the citronella plant develop a bushier shape and more robust foliage.
- Citronella plants growing indoors that are not getting enough sunshine will let you know by developing etiolated foliage. Plants that are etiolated have leggy, weak stems that look stretched out and tend to collapse under the plant’s weight. If this happens to your plant, first you’ll need to prune to clip away any areas that are etiolated. Then find a sunnier spot for your citronella plant, one that gets at least six hours of daily sunshine. Windows that face west or south tend to be ideal.
- Allow the top inch of your indoor citronella plant’s soil to dry out before watering the plant again. It’s easy to test the moisture level of your soil. Simply stick a finger into the soil where your citronella plant is growing, going at least an inch under the surface. If you feel moisture or the dirt clings to your skin, it’s not yet time to water your citronella plant again. Ideally, you want the top inch of the soil to dry out without all the soil in the container drying out completely.
- Water the base of the plant, not its foliage or the surrounding soil. Plants can only absorb water through their root system, so water too far away to reach or water splashed on the plant itself is wasted and doesn’t help hydrate your plant. Also, excess water on foliage can contribute to the spread of fungal diseases. Prevent these issues by only watering the soil at the base of your citronella plant. One to two inches of water per week is a good starting point.
- If your citronella plants don’t get enough water and sunshine, they might go into dormancy. You can learn more about dormancy in our article Dormant Plants: Your Top Questions and Answers. While a dormant plant won’t need as much care, it also won’t flower or produce new growth. Prevent this by keeping your citronella plant appropriately watered and providing enough sunlight (at least six hours of direct sunlight every day).
- Citronella plants that you keep indoors benefit from a bit of light pruning over the winter. During the cold season, pinch back any new leaves or new shoots your plant puts out. This will coach the plant into a compact, bushy silhouette and make sure you have plenty of new growth during the spring.
- Give citronella plants occasional doses of plant food diluted to half strength to make sure they grow healthy and strong. A good schedule is giving the first dose when you plant the citronella, and then giving small amounts every few weeks.
Not only is it possible to grow citronella plants indoors, but in most zones with cooler climates it’s a requirement to keep your plants alive all year. Following the instructions here, you’re prepared to plant, propagate, and care for citronella geranium plants indoors and enjoy the lovely citronella scent all winter.