Learn how to cultivate and maintain a healthy citronella plant

If you're looking to add something fresh to your garden this season, think about the citronella plant. Perfect for window boxes or patio containers, this plant boasts delicate green, fern-like leaves and bright pink flowers. With minimal care, you'll be rewarded with blooms during the summer months. Here’s a complete guide to growing citronella, according to horticulture experts.

What exactly is a citronella plant?

The citronella plant, scientifically known as Pelargonium graveolens, is a perennial or annual depending on the climate. In USDA Hardiness Zones 9 to 11, it thrives as a perennial. However, in colder zones that experience winter freezes, citronella behaves as an annual and should be brought indoors before the frost arrives.

Distinction between Citronella Plant and Citronella Grass

Though both share similar names, the citronella plant and citronella grass belong to different botanical families. According to John Saltiel, a gardener at the United States Botanic Garden, "They aren't remotely related." He further explains, "One resembles a geranium, while the other is more like common grass."

The main shared trait, as Tim Pollak from the Chicago Botanic Garden mentions, is their unmistakable scent. Additionally, the oil from the citronella plant might offer temporary mosquito relief if its leaves are crushed and applied to the skin. For more effective mosquito repellent, however, products containing citronella oil derived from citronella grass are the better choice.

Tips for Caring for a Citronella Plant

Although the citronella plant can thrive indoors in a pot, it tends to prefer the outdoors. Tim Pollak suggests planting it in a container outside to easily manage its exposure to light and moisture, and moving it inside for the winter if you live in a colder region. No matter the climate, here are some additional key care tips for maintaining a healthy citronella plant.

Sunlight

Citronella plants do better with more light, and without sufficient exposure, they can become spindly. As Pollak states, "A plant with more light will grow stronger and bloom more." While citronella can tolerate direct sunlight, it thrives in bright, filtered light—such as that found under a tree or on the west side of your house, where it avoids prolonged exposure to harsh sun.

Soil

Citronella plants thrive in a variety of soil types. Opt for a potting mix that helps retain moisture around the roots, such as one made with peat moss. Pollak advises, "Avoid using regular, heavy garden soil, as it tends not to hold water well." The goal is to ensure the soil holds moisture between waterings. A combination of perlite, peat moss, and garden soil can also promote healthy plant growth.

Watering

Even if your citronella plant is outdoors, don't depend on rainfall alone to water it. Be sure to check the soil regularly and water thoroughly when the top few inches feel dry. Pollak warns not to wait too long: "If the soil dries out, the lower leaves will start to yellow, and eventually, older leaves will drop off."

Temperature and Humidity

Citronella plants are hardy and can tolerate temperatures from the upper 30s to 90°F. However, if the temperature drops below freezing or exceeds 90°F, it's best to bring your plant indoors as extreme conditions can harm it. Saltiel notes that excessive moisture can lead to rot—citronella prefers humidity levels between 40% and 70%.

Fertilizing

Using fertilizer can help keep your citronella plant healthy and encourage it to bloom during the summer. Pollak suggests fertilizing the plant once a month while it is actively growing in the spring and summer, then stopping once fall arrives. A balanced fertilizer that includes magnesium is ideal for promoting the best growth.

How to Propagate Citronella

If starting a citronella plant from seed isn't your preference, you can easily propagate it from a cutting.

1. Select your cutting. Use scissors or pruning shears to cut a 2 to 3-inch section from a healthy stem. The cutting should have two nodes (the bumps where new growth, including stems, leaves, and buds, forms).
2. Trim the leaves. To help the cutting root, leave only two leaves on the stem, ideally at the tip of the cutting.
3. Apply rooting hormone. Unlike with succulents, there’s no need to let the stem dry out before planting. However, adding a store-bought rooting hormone to the bottom of the cutting may help stimulate growth.
4. Plant the cutting. Place the cutting, bottom-end first, into a small pot filled with soil. Keep the leaves moist—spritz them regularly or create a humid environment by covering the cutting with the lid of a cherry tomato container. Pollak advises that a consistently moist atmosphere will promote rooting, and roots should form within a month!

Common Citronella Issues and Solutions

While citronella plants are generally hardy and face few problems, there are a couple of issues that can occasionally arise. Here’s how you can address them when they do.

Pests

Like many outdoor plants, citronella can be susceptible to pests like whiteflies, aphids, and mealybugs. If you spot any of these insects, blast them off with a strong stream of water. In case of a larger infestation, it’s advisable to repot the plant and treat it with insecticidal soap.

Legginess

If your citronella plant appears leggy (thin), it's usually due to insufficient sunlight. This issue can be easily fixed if the plant is potted. If it's in your garden, you may need to adjust its placement to ensure it gets the proper amount of sun.

Browning Leaves

Browning leaves on a citronella plant are often caused by too little sunlight. Try moving your plant to a spot that receives at least six hours of sunlight each day. If that doesn’t solve the issue, overwatering might be the problem.

Yellowing Leaves

Yellowing leaves are usually a sign of poor air circulation and overwatering. Excess water can lead to root rot, so it's important to be careful not to overwater your citronella. Allow the soil to dry out between waterings whenever possible.

Root Rot

All plants in the geranium family are predisposed to root rot, which is usually caused by too much water. The overabundance of moisture causes the roots to decay under the soil, so it's not always the most obvious problem. Watch out for signals; the first sign is yellowing leaves, but root rot can kill your plant when left unaddressed.

Crown Rot

Crown rot happens when bacteria or fungi attack the plant. You can spot it by looking for browning where the plant meets the stem. Unfortunately, crown rot is almost impossible to eradicate, so it's best to get rid of the plant and start over.

Damping Off

Damping off is a condition caused by a fungus that flourishes in moist, cool environments. One of the signs of damping off is crown rot, which is essentially decay beginning at the seedling or in the soil. To prevent damping off, be cautious not to overwater.

Frequently Asked Questions

• What animals are attracted to citronella plants?

  Citronella plants draw various types of bees, such as bumblebees, mason bees, miners, and more. They also attract March flies, syrphid flies, and small butterflies. Aside from insects, chipmunks enjoy eating the seeds, and deer sometimes nibble on the leaves and flowers.

• Are citronella plants toxic to pets?

  Yes, citronella plants belong to the geranium family, and all geraniums are harmful to pets. If your pet consumes citronella, it may suffer from various symptoms, including vomiting, loss of appetite, and more. If you suspect your pet has ingested citronella, contact your veterinarian immediately.

• Does citronella repel mosquitoes?

  Crushing the fragrant leaves of citronella and applying them to your skin may help repel some bugs, but don’t expect the same results as commercial bug repellents. The citronella plant emits a pleasant lemon scent, which some believe may deter pests. However, simply growing citronella is unlikely to have much effect on insects, according to Saltiel. "I’ve used it myself, and I’ve noticed its effects were only brief, which makes it not very practical."