Citronella grass and lemon grass differ by a single genetic marker, leaving them with a lot of similarities when it comes to appearance and smell, but the differences are profound.
Lemon grass is completely edible and makes a safe, healthy and delicious herbal tea, while citronella grass is used for cleaning products, mosquito repellants, deodorants, perfumes and soaps and is not meant to be consumed internally.
Ingesting citronella grass usually doesn’t cause any short term problems, but long term consumption could result in lung damage, increased heart rate and skin allergies.
Both plants have spear type leaves and can grow to heights of five to six feet (three meters).
Lemon grass is narrow, light green in colour, with a pleasant lemon smell that makes a light, sweet tasting tea.
Citronella grass has wide blades, is deep green in colour and has a very strong smell and taste.
If your citronella plant has wide lacy type leaves it is not citronella grass, but a citronella geranium commonly marketed as Mosquito Plant for its supposed mosquito repellant qualities.
Whether or not the citronella geranium plant actually helps keep mosquitoes at bay simply by being placed on a patio is the subject of much debate. Whether it works or not, it is still a worthy, robust, pretty plant with a wonderful scent and lovely purple blooms.
If keeping mosquitoes from packing you off for their supper is your goal, the take away here is that mosquitoes hate the smell of lemon. Use that knowledge wisely.