Citronella Grass (Cymbopogon nardus and C. winterianus)

Plant Snapshot

Common Name: Citronella Grass
Latin Name: Cymbopogon nardus / C. winterianus
Hardiness Zones: USDA 9–11 (frost tender; in colder zones grow as an annual or overwinter in containers)
Typical Height: 3–6 ft (90–180 cm) tall
Typical Spread: 2–4 ft (60–120 cm) wide clumps
Bloom Period: Late summer to fall small, inconspicuous flowering heads; not grown for blooms
Soil Preferences: Fertile, well drained soils. Tolerates sandy to loamy soils. Avoid waterlogged heavy clay which causes root rot
Light Preferences: Full sun for best growth and fragrance. Tolerates light afternoon shade but may become leggy
Toxicity: Foliage is not known to be highly toxic but citronella essential oil can irritate skin and may upset stomach if ingested by people or pets. Keep concentrated oil away from pets and consult poison control for exposures
Propagation: Division of clumps is the primary method. Stem cuttings and seed are possible but division is fastest and most reliable

Key Facts

Aromatic clumping perennial grass grown for fragrant foliage and citronella oil
Used as a landscape accent and for its mosquito repellent scent
Frost tender and treated as perennial only in warm climates
Prefers full sun and well drained soil
Propagated most reliably by division of clumps
Produces small, inconspicuous flower heads in warm months
Essential oil can irritate skin and can upset stomach if ingested

Citronella Grass (Cymbopogon nardus and C. winterianus) is an aromatic clumping grass prized for fragrant foliage and the citronella oil it produces. It works well as a landscape accent or in containers to give scent and some mosquito repellent properties, but it is frost tender and needs protection in cool climates.

Identification

Clumping perennial grass that typically reaches about 3 to 6 feet tall with clumps 2 to 4 feet wide. Leaves are narrow and fragrant when crushed. Small inconspicuous flower heads appear in the warm season from late summer to fall and are not the main ornamental feature.

Best uses and where to grow

Use as a specimen accent, informal border or patio container to benefit from scent and foliage texture. Best grown in warm climates where frosts are absent USDA zones 9 to 11. In cooler areas it is commonly grown as an annual or kept in containers and moved indoors for winter.

Planting and spacing

Plant in spring after risk of frost or in early summer for quick establishment. Space plants roughly 2 to 4 feet apart to allow full clump development and air flow. Choose a site in full sun for the strongest fragrance and most compact growth.

Water and soil

Prefers fertile well drained soils and tolerates sandy to loamy mixes. Keep soil consistently moist while plants establish. Avoid waterlogged heavy clay because poor drainage leads to root rot and decline. Reduced sun and poor soil lower oil production and vigor.

Care through the seasons

Remove damaged foliage and tidy the clump as needed. Divide and renew plants in spring or early summer to maintain vigor and size. Frost causes dieback in colder weather so expect seasonal loss of top growth outside warm zones.

Propagation and division

Division of established clumps is the fastest and most reliable method. Lift and separate tufts in spring or early summer for best establishment. Seed and stem cuttings are possible but less common for garden production.

Containers and winter care

Container culture is ideal for cooler climates because pots can be moved indoors to overwinter. Treat outdoor plantings as annuals where hardiness is below the listed zone range. In containers use a well drained potting mix and avoid overwatering in winter.

Controlling spread

Plants form clumps and are not highly invasive but may slowly expand by short rhizomes in warm conditions. Control size with regular division and remove offshoots if they appear. Check regional guidance before planting if invasive species are a concern in your area.

Frequently asked questions

How fast does Citronella Grass grow?: Growth varies with climate and fertility but plants commonly reach 3 to 6 feet tall in a single warm season. Growth is faster in fertile warm sites with regular water.
Is Citronella Grass safe for pets?: Foliage itself is not known as highly toxic but concentrated citronella oil can irritate skin and can upset the stomach if ingested. Keep oils away from pets and consult poison control for exposures.
Can I grow Citronella Grass in a container?: Yes. Containers are a good option in cooler climates because pots can be brought indoors for winter. Use a well drained mix and water to keep roots from becoming waterlogged.
When should I divide Citronella Grass?: Divide established clumps in spring or early summer to renew plants and control size. Smaller divisions establish more quickly when done during active growth.
Does Citronella Grass repel mosquitoes?: The foliage produces citronella scented oil that people use as a mild mosquito repellent in gardens and patios. Plants offer some local scent benefits but are not a guaranteed substitute for repellents in all situations.