How to Grow Lemongrass and Citronella in a Dome Greenhouse

Growing lemongrass and citronella in your dome will provide you with beauty, culinary uses for lemongrass and medicinal uses from both plants.

Lemongrass

• Family:Poaeceae
• Botanical Name: Cymbopogon citratus
• Common Name: Lemongrass, barbed wire grass, citronella grass
• Type: Perennial, annual
• Light: Full
• Soil pH: Neutral, acidic
• Zone: 10-11 (USDA) – Can be extended in a dome
• Size: 2-4 ft. tall, 2-4 ft. wide

Note: Lemongrass is toxic to pets.

Citronella Plant With Flowers

• Family:Geraniaceae
• Botanical Name: Pelargonium (scented-leaved group)
• Common Name: Citronella plant, scented geranium, mosquito plant
• Type: Tender perennial, annual
• Light: Full to part sun
• Soil pH: Acidic, neutral
• Zone: 10-11 (USDA) – Can be extended in a dome
• Size: 1-3 feet tall and 1-2 feet wide

Note: The citronella plant is toxic to pets, mildly toxic to humans, can cause skin irritation

Growing Lemongrass and Citronella Plants

Growing sun-loving lemongrass and citronella plants in your dome is fun and functional!

Best Location in a Dome

Both lemongrass and citronella plants prefer full sun. However, they have different heat tolerances. Lemongrass likes the heat as well as full sun whereas citronella plants prefer cool, early morning sun and a bit of afternoon shade.

Place these plants near the pond for warmest temperatures throughout the winter.

Note: Citronella plants can have a strong smell so consider whether or not it is appropriate for your growing dome and your sense of smell.

Planting

Lemongrass can grow quite tall and wide so it is best to leave 2-3 feet of space between plants. It will also create shade so consider what to plant nearby and what the light requirements are for companion plants.

Planting lemongrass is very similar to onion slips. Plant the bulbs with the bottoms of the bulb at the soil line with the roots buried.

Citronella plants do well in a pot or container. This will enable you to easily move it outside of the greenhouse. If your dome is unheated, move your potted citronella plant in your home for winter.

To grow citronella plants in a container or pot, choose one that is a minimum of 12 inches deep. The container should also be at least twice as wide as the root ball. A good soil that drains well is important. One method is to mix your own soil adding in sphagnum moss or sand. The air temperature must be 50 degrees or warmer at night.

If you plant a citronella plant in your dome it needs well-draining loamy soil that is fertile. Plant the root ball one foot deep. To plant by seed, sow them lightly over the soil.

Lemongrass and Citronella Care

Light

As mentioned above, both plants need full sun. The difference is that lemongrass can tolerate the heat of the afternoon sun and citronella plants prefer morning sun with afternoon shade. Citronella plants need at least six hours of sun per day.

Soil

These two plants do have different soil needs. Lemongrass needs a rich, loamy soil that holds nutrients and water, but drains well.

Citronella plants prefer a well draining sandy loam soil. Although it is a very adaptable plant it does best at a pH level between 5.8-6.3. We always recommend testing your soil.

Water

Lemongrass benefits from regular watering as it is a thirsty plant that also loves humidity. Keeping the soil moist, but never soggy will keep it happy. It is not drought tolerant.

Citronella plants can be watered every few days in the greenhouse. One of the cardinal rules of watering these plants is “less is more”.

However, they will need more frequent watering if planted in a pot. Check the soil and water as necessary. If the leaves are looking brown and crispy, increase your watering. If the leaves are looking yellow, cut back on watering.

Temperature

Neither lemongrass nor citronella plants will handle freezing temperatures or frost. They both prefer warmer temperatures and thrive in Zones 10 and 11.

Citronella plants love humidity and as a tropical plant handle 40 percent humidity well. Keep a mist bottle nearby! However, these plants do not do well in high temperatures.

Fertilizer

Lemongrass is a thirsty plant and needs nitrogen for those beautiful arching leaves. Consider using a water-soluble nitrogen fertilizer or compost tea. Another option is applying a slow-release nitrogen rich fertilizer weekly during the summer growing season.

Young citronella plants will benefit from a liquid NPK 20-20-20 fertilizer every few weeks during the growing season. Mature citronella does not require much fertilizer.

Pruning and Harvesting

Pruning

Lemongrass can be pruned to 6 inches tall for the winter to about 6 inches tall. Trim away any dead leaves. It can rebound when warm weather returns. If your dome is not heated, it may be an annual plant.

Citronella plants can be pruned throughout the growing season, especially if you want to shape its growth. A pinch here and there will do the trick. In an unheated dome, it is an annual plant.

Harvesting

To harvest lemongrass use a small shovel or trowel and remove the stalk and roots from the clump. Young lemongrass plants can also be harvested.

Citronella is not an edible plant, although some varieties have been used for flavorings. Pelargonium species that have been used for medicinal purposes in their native Africa.

Best Companion Plants

Lemongrass has many friends and most of them are herbs! Basil, chives, cilantro, echinacea, lemon verbena, marigolds, oregano, thyme and tomatoes. Mint also grows well with lemongrass, but it will take over your dome so we don’t recommend planting it in your beds.

Another thing to remember is that lemongrass is taller than its friends so be sure they have the right amount of sunlight. Plant them around the lemongrass where they will not be in the shade.

Citronella plants do well with neighbors such as basil, chives, lavender, lemon balm, marigold, nasturtium, rosemary and thyme. (Did you just sing those last two words? If that song is before your “thyme” take a listen to the song.)

Pests

Lemongrass is pretty hardy, but those pesky aphids and spider mites seem to like every variety of ornamental plants. Using a sprayer on your garden hose can knock them down or try insecticidal soap or neem oil to deal with them.

Rust fungus is a disease that can affect lemongrass plants by leaving streaks on the leaves or brown spots. It can kill your plant if left untreated. One way to help prevent it is to water your plants at the soil level rather than the leaves.

For the most part, the citronella plant is fairly disease-free. Aphids, whiteflies, leafhoppers, weevils and mealy bugs are attracted to these plants. A strong spray of water can eliminate them if you discover it early. It’s always good to spend time checking your plants, don’t forget to look under the leaves!

Avoid root rot and crown rot by careful watering. Citronella plants do not like to be in standing water.

The History of Lemongrass and Citronella

Lemongrass may have originated in Malaysia and is native to various countries in Southeast Asia. It is first recorded as a cultivar in 17th century texts (not text messages!) from the Philippines.

It wasn’t until around 1905 that there was much interest in lemongrass. J.F. Jovit was a researcher from Sri Lanka and started studying it. By 1917 lemongrass had been introduced to Haiti and tropical locations in the United States. Just 30 years later it was commercially cultivated in Haiti and Florida.

India is the number one exporter of lemongrass products.

The citronella plant is native to the Cape Provinces, northern South Africa, Zimbabwe and Mozambique. Around 1795 these plants traveled from the Cape of Good Hope with the British fleet.

In England they were quite successful with their beautiful colors and variety of fragrances. Indeed, the rose geranium was rather talented at mimicking the costly attar of roses’ famous scent.

Scented geraniums have a variety of aromas from rose to cinnamon. In Kate Greenaway’s 1884 book, Language of Flowers, she described the rose geranium’s meaning as “preference”.

In 1932 Louise Beebe Wilder wrote about rose geraniums in the book, The Fragrant Path. She suggested using the leaves as “a delightful frill for a bunch of sweet peas or stocks or combining rose geraniums and nasturtiums for a stimulating nosegay.”

Lemongrass and Citronella Plant Trivia

• Did you know lemongrass oil attracts honey bees?
• Lemongrass is a tall, beautiful and edible plant, but you can also use it in body scrubs and soaps.
• Here are some other uses of lemongrass: perfumes, soaps, disinfectants, pest repellents and scented candles.
• The citronella plant itself is not a mosquito repellent. The oil within the leaves helps deter them, but it is not highly effective. Have you tried our bug repellent salve recipe?
• Did you know crushing citronella leaves and spreading them might deter rodents, flies and ants? The strong odor may be something they don’t like so you may consider adding it to your pest control repertoire.
• The citronella plant (Pelargonium – scented-leaved group) is called scented geranium or mosquito plant. Lemongrass is sometimes called citronella grass, but citronella grass is different from lemongrass and citronella grass is also called nard grass. Whew! Clear as mud?

Uses for Lemongrass and Citronella Plants

Lemongrass is a common ingredient in Thai cuisine. It is also used medicinally for digestive issues and high blood pressure.

Note: Lemongrass can cause skin irritation. If you have experienced an allergic reaction it is wise to avoid ingesting it. Some sources also recommend pregnant women avoid lemongrass.

Some of the benefits of lemongrass are iron, calcium, vitamin c and it is a wonderful source of flavonoids. It also contains phenolic compounds and those contain antioxidants.

It is thought to have antibacterial and anti-fungal properties and has been used for pain relief as well as to reduce fevers. That is due to citral, which is a natural plant compound that has anti-inflammatory effects.

Citronella plants are cultivated and distilled by the perfume industry for their scents. Some varieties are used for flavoring desserts and teas. The scents most frequently used are rose, lemon, and peppermint. As an herb, pelargonium has been used for a variety of ailments.

Try growing lemongrass and citronella plants in your dome this season. Happy gardening!