Citronella Grass vs Lemongrass

Written by Becky Mathews
Published: October 27, 2022
© Travel_Master/Shutterstock.com
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Citronella Grass and Lemongrass are very similar plants, so it’s no wonder people get them mixed up. They may smell the same and look almost identical, but there are some strong differences, the most obvious being their culinary use. Let’s take a closer look at Citronella grass vs Lemongrass and find out how to tell them apart.

Citronella Grass vs Lemongrass

Key Similarities

Both citronella grass and lemongrass are clump-forming grasses that smell like lemons. They have narrow foliage, repel bugs, and they both have specific uses. In summer they have almost identical grassy flower spikes.

Key Differences

The main differences are the leaf color, height, and their uses. Lemongrass is used extensively in South Asian cuisine whereas inedible citronella grass is distilled into citronella oil for our cleaning products and anti-bug supplies. Visually, citronella is the larger of the two foliage clumps and it has some red shades, but lemongrass is entirely green.

NameCitronella Grass Cymbopogon nardusLemongrass Cymbopogon citratus
FoliageStrappy long green leaves over a foot-long red at the base, slightly wider than lemongrassStrappy long green leaves, entirely green,
Height And SpreadSix feet by four to five feetFour feet by four feet
FlowersGrass-like creamy brown flower spikesGrass-like creamy brown flower spikes
Growing Zone9-119-10
UsesOrnamental in the garden commercially for essential oilOrnamental, edible.
ToxicityToxic to petsToxic to pets

Citronella Grass and Lemongrass Classification

Citronella grass sits in the grass family Poaceae in the Cymbopogon genus. Its botanical name is Cymbopogon nardus or sometimes Cymbopogon winterianus, but it’s more commonly called evergrass, barbed wire grass, silky heads, Cochin grass, or oily heads. Citronella gets its name from the French word ‘Citronelle’ which means rather confusingly means lemongrass!

Lemongrass also sits in the Poaceae grass family in the Cymbopogon genus of plants. Its botanical name is Cymbopogon citratus and there are around 45 different types and cultivars of lemongrass. It’s a frequent candidate under investigation for its medicinal and preservation properties.

The origins of their classification are interesting, so let’s read up before we move on!

Did you know There are 144 grass species in the Poaceae family, including bamboo? It’s not just the short green stuff that makes up a lawn, also, Cymbopogon is pronounced “kym-bo-pogon” which is Greek for boat-beard and describes its boat-like flower spathes.

Fascinating stuff.

Lemongrass
Lemongrass also sits in the Poaceae grass family in the Cymbopogon genus of plants

©Nannie_iiuu/Shutterstock.com

How Are They Used Differently?

Even though they are members of the same genus, citronella grass and lemongrass are used very differently.

Lemongrass is a favorite herb in South Asia where its stalk is used to flavor food, distilled into tea, and added to all types of dishes to add a clean fresh taste.

In contrast, citronella grass is harvested for its essential oils that are included in mosquito repellents, cleaning products, and cosmetics. Millenia ago the Ancient Greeks, Romans, and Egyptians used citronella grass to repel lice and bed bugs. It’s been helping us stay clean and healthy for thousands of years.

Lemongrass
Lemongrass is a favorite herb in South Asia where its stalk is used to flavor food, distilled into tea, and added to all types of dishes to add a clean fresh taste.

©NIKCOA/Shutterstock.com

Native Ranges

Lemongrass and citronella are native to tropical regions. They both hail from Australia, Africa, Asia, and some small Pacific Islands, but are widely grown in tropical south and north America, the Mediterranean, and southern Europe.

Are Lemon Grass and Citronella Perennial?

Both species are perennial in their native tropical habitats, but they can tolerate freezing temperatures, so Northern Europeans and cold Zone north American gardeners grow them as annuals. This means letting them die off over winter and replacing them in spring.

What Are the Foliage Differences?

They are both clump-forming perennial grasses with a fountain of green narrow foliage, but there are a few differences here.

Citronella grass has reddish-colored stems at the base, particularly on new growth whereas lemongrass foliage remains green along its entire length no matter how new its leaves are.

Citronella has a wider leaf blade that can reach over an inch wide. In contrast, lemongrass blades are ½ an inch wide.

One final foliage difference is the mature clump’s height. Lemongrass tops out at two to four feet in height and width but citronella grass is much bigger. It can reach six feet tall and spread over four to five feet.

It also has a much more extensive root system. It’s not possible to see that, but it does mean that citronella grass is better at sucking up water and nutrients. When they’re planted together, it can outcompete lemongrass and live an extra few years.

Does Citronella Grass Flower?

In summer, citronella grass and lemongrass develop grassy brown-cream flower spikes that emerge from the foliage clump’s center. These spikes are topped with white tubular sprays of compound flowers that look much like the seedheads they eventually mature into.

Citronella Grass vs Lemongrass: Growing Zones

These flowering grasses are tropical heat lovers, so it’s no surprise they need hot Zones. Both will grow in Zones 10 to 11, with citronella grass able to take on the hotter Zone 11 as well.

Neither will cope with winters in Zone 9 and below.

How To Grow Citronella Grass vs Lemongrass

Lemongrass and citronella have very similar care requirements which means you can grow them together if you want to.

The most important aspects are well-drained soil, shelter, and full sun. Both need at least six hours of full sun a day, but citronella grass will cope with a little partial shade. Make sure the plants have shelter from gusting winds that create a chill.

Any fertile well-drained soil is suitable and they with grow in a well-watered and fed container as well. It’s very handy to have a container of delicious lemongrass by the kitchen door!

Unless you’re in a tropical Zone winter is a dangerous time for citronella grass and lemongrass. As we know, they can’t cope with winter in Zone 9 and below. The best idea is to dig them up and bring them inside. They will enjoy a sunny window sill over winter.

Snow covered Yellowstone National Park in Wyoming
Unless you’re in a tropical Zone winter is a dangerous time for citronella grass and lemongrass.

©iStock.com/Jonathan Steele

Are Citronella Grass and Lemongrass Toxic For Dogs?

The ASPCA says Lemongrass and citronella grass are toxic. It’s because they contain so much essential oil and cyanogenic glycosides. Thankfully it takes a lot to make pets unwell, but it’s best to keep chewing dogs, cats, rabbits, and horses away from them. The symptoms include vomiting and an upset stomach, but it can cause horses to collapse.  

Do They Keep Mosquitoes Away?

Lemongrass and citronella grass are well known for their citron essential oils that keep mozzies at bay. Although lemongrass has a lemony scent, it’s citronella grass that contains the most essential oil and it’s harvested on a commercial scale as a result.

Some gardeners say growing these two types of grass can keep bugs away, but research indicates their presence isn’t enough. To keep mosquitoes out of your home and garden you need a distilled version of citronella grass. This article from the National Library of Medicine suggests anything else is no more effective than water.

However, boiling up a solution of lemongrass or citronella grass in water may temporarily banish mosquitoes from a room. It also helps deter aphids from your plants too. Just spray it liberally on stems and shoots for an all-natural bug deterrent. You’ll need to apply it regularly, but it’s better than applying chemicals that kill beneficial pollinators.

What About Spiders?

The majority of animals don’t like the smell of citrus so any lemony scent you use can help keep pests at bay, including spiders!

Is Lemongrass Better Than Citronella Grass?

Both species are attractive and have a refreshing scent in the garden. Citronella grass gets larger and has red base stems so it’s easy to tell them apart, but lemongrass is better if you plan to use it in the kitchen. It has a host of uses in Asian foods and makes a refreshing delicious tea. Citronella grass is inedible!

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The Featured Image

Citronella Grass
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About the Author

I’ve been a professional writer since 2014 with special interests in the environment, particularly endangered animal and plant species. I graduated from the University of Reading, UK with an MA in history and hold University of Oxford qualifications in archaeology. Outside of work, I rehabilitate wildlife, work in my allotment garden, and play the piano badly.

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Sources
  1. , Available here: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/t?&