There are two ways to make citronella oil with coconut oil: infuse fresh citronella leaves directly into coconut oil using low heat, or dilute store-bought citronella essential oil into coconut oil as a carrier. Both produce a topical oil you can use as a natural mosquito repellent, though the essential oil method is faster and more potent. Here’s how to do each one.
Method 1: Infusing Fresh Citronella Leaves
If you have a citronella plant (sometimes sold as citronella grass or lemongrass), you can extract its oils directly into coconut oil using a slow-cook infusion. You’ll need about 2 to 3 cups of fresh-cut citronella leaves and roughly 2 cups of coconut oil.
Start by washing the leaves and bruising or roughly chopping them to help release their oils. Place the leaves and coconut oil together in a slow cooker or double boiler and heat on low for about 4 hours. The gentle, sustained heat draws the plant’s aromatic compounds into the oil without burning them off. After 4 hours, strain the mixture through cheesecloth or a fine mesh strainer, pressing the leaves firmly to squeeze out as much oil as possible. Pour the finished oil into a clean glass jar.
This method produces a milder product than using concentrated essential oil. The infusion will smell pleasantly citrusy, but its repellent strength is lower, so you’ll need to reapply it more frequently when using it outdoors.
Method 2: Diluting Citronella Essential Oil
The quicker approach is to buy citronella essential oil and mix it into coconut oil at the right ratio. A safe starting point for skin application is 3 drops of citronella essential oil per 1 teaspoon of coconut oil. This gives you a concentration strong enough to work as a repellent while keeping the risk of skin irritation low. You can scale up proportionally for larger batches.
Never apply undiluted citronella essential oil directly to your skin. Essential oils are highly concentrated, and citronella’s primary safety concern is skin irritation. Coconut oil acts as a carrier that spreads the active compounds across your skin at a safe concentration.
Which Coconut Oil to Use
Your choice of coconut oil type affects both convenience and shelf life. Fractionated coconut oil stays liquid at any temperature, mixes easily, and has one of the longest shelf lives among carrier oils. It’s the most practical option for a repellent you’ll grab and apply quickly.
Unrefined (virgin) coconut oil retains more of its natural fatty acids and antioxidants, but it solidifies below about 76°F. That means you may need to warm it between your hands before each use, and it can turn your repellent into a semi-solid balm in cooler weather. Either type works, but fractionated coconut oil is the easier choice for something you’ll keep by the door all summer.
How Citronella Repels Mosquitoes
Citronella doesn’t kill insects. It works by masking the human scents that mosquitoes use to find you, like carbon dioxide and body odor. When mosquitoes can’t detect those signals, they have a harder time locating you to bite. This masking effect is why citronella-based repellents need frequent reapplication: once the scent fades, your natural attractants become detectable again.
How Often to Reapply
Plan to reapply your citronella oil every 1 to 2 hours when you’re outdoors. If you’re sweating heavily or swimming, reapply sooner. This is significantly more frequent than synthetic repellents like DEET, which can last 6 to 8 hours per application. Apply to exposed skin, avoiding your eyes and mouth. The oil can also be rubbed onto clothing or a bandana for a less direct approach.
One note on pets: citronella oil can be applied to a dog’s collar to help repel insects, but do not use it on or around cats. Many essential oils are toxic to them.
Boosting Effectiveness With Other Oils
Combining several plant-based essential oils tends to produce a stronger repellent than any single oil alone. Research published in BioMed Research International found that blending oils from different plant families creates a synergistic effect, meaning the combination repels mosquitoes more effectively than you’d expect from adding each oil’s effect together.
Good additions to a citronella and coconut oil base include lavender and peppermint oils, both of which have shown repellent activity on their own. Keep any added essential oils at the same safe dilution ratio (a few drops per teaspoon of carrier oil) and do a small patch test on your inner forearm before applying a new blend widely.
Storage and Shelf Life
Store your finished oil in a dark glass jar with a tight-fitting lid, kept in a cool place away from direct sunlight. Essential oils don’t go rancid the way cooking oils do, but they oxidize over time, gradually losing their aromatic strength and repellent properties. Your carrier oil is actually the weaker link: coconut oil (especially unrefined) will eventually go rancid. If it starts to smell off or looks discolored, make a fresh batch.
Fractionated coconut oil lasts significantly longer than unrefined, so blends made with it can stay effective for several months. For leaf-infused oils, which lack preservatives, aim to use your batch within a few weeks and store it in the refrigerator to slow degradation.