Lemon myrtle (Backhousia citriodora) is a compact evergreen tree native to Australia. The lemon-scented leaves can be used for cooking and flavoring. While lemon myrtle isn’t common in the United States, it’s worth giving it a go. In this article, I’ll share my experience of growing and caring for lemon myrtles.
About Lemon Myrtle
Family & Genus
Lemon myrtle is part of the myrtle family (Myrtaceae). But unlike true myrtles, lemon myrtle comes from the Backhousia genus. The genus is named after James Backhouse, a 19th Century botanist, and missionary.
Lemon myrtle is endemic to southeastern Queensland in Australia. Lemon myrtle is native to subtropical rainforests in this region. As such, lemon myrtle grows best in USDA Zones 10 to 11.
Lemon myrtle is a compact evergreen shrub or tree. In its native habitat, lemon myrtle grows up to 25 feet high but only reaches approximately 16 feet high in gardens. Lemon myrtle is also known as lemon backhousia or sweet verbena myrtle.
Lemon myrtle is highly prized for its fragrant lemon-scented foliage. These evergreen leaves are elliptical or lanceolate. These shrubs also produce rounded clusters of white flowers with long stamens. The flowers also give off a delicate scent and bloom in the summer.
Meaning & Symbolism
Like true myrtle flowers, lemon myrtle is associated with love, beauty, and romance. It’s also a symbol of marriage in many cultures. Lemon myrtle’s white flowers are also linked to innocence, peace, purity, and rebirth.
Uses & Benefits
Lemon myrtle is a common culinary herb in Australian cooking. Lemon myrtle was first used extensively by Aboriginal peoples and is considered to be a bush tucker food. Dried lemon myrtle leaves are used to flavor baked goods or fish and can also be turned into tea.
Lemon myrtle is also used to make an essential oil that has antimicrobial properties. However, it must be diluted to be safe for humans to use. Lemon myrtle also makes a fantastic fragrant ornamental shrub in the garden.
How Tall, Wide, and Fast Do Lemon Myrtles Grow?
Lemon myrtle grows between 20 and 25 feet high and approximately 16 feet wide in its native habitat. However, it stays relatively compact in gardens and rarely gets above 16 feet high. Lemon myrtles are slow to grow as seedlings or as cuttings. Lemon myrtles take approximately 3 to 4 years to reach full maturity.
How to Grow and Care for Lemon Myrtle
Where and How to Plant Lemon Myrtle
Lemon myrtle needs full sun to partial shade and fertile, well-draining soils that still retain moisture. These adaptable shrubs can tolerate various types of soil. However, they do prefer slightly acidic soils with a pH range between 5.5 and 6.5.
Dig a hole that’s as deep as the root ball and twice as large. Add organic matter such as compost or manure to provide nutrients. Place the lemon myrtle’s root system into the soil and fill in around it before watering it in. Lemon myrtles can also be grown in containers.
Lemon myrtle needs full sun or partial shade to produce its best flowers. Lemon myrtle requires about 6 hours of direct sunlight daily in warm climates. However, lemon myrtle shrubs need partial shade in hot, dry climates.
Lemon myrtle shrubs thrive in most soils as long as the conditions are well-draining. For optimal growth, they require moderately moist soil but hate being waterlogged. IN addition, lemon myrtles also need slightly acidic soils with a pH level between 5.5 and 6.5.
Temperature & Humidity
Lemon myrtles are native to subtropical rainforests, so they need warm, humid conditions to grow at their best. They can tolerate cooler climates, but this can inhibit the size of the plant. In addition, lemon myrtles struggle when exposed to frost, so grow them in containers and move them indoors in cooler climates.
Water established lemon myrtle shrubs approximately once a week if the soil feels dry (more frequently in hot, dry summers). Water young or newly planted lemon myrtles regularly to help them establish good roots. This takes approximately three years.
Feed lemon myrtles once a year after the flowering season finishes. Use slow-release fertilizer granules or apply a diluted liquid fertilizer. Always follow the instructions on the fertilizer packet.
Avoid harvesting leaves from your lemon myrtle straight after it’s been fertilized. The ingredients in the fertilizer can affect the taste of the leaves.
Prune lemon myrtle shrubs at any time of the year. However, the best time is in winter or late spring when the shrub is dormant. Lemon myrtles can be easily trimmed or shaped to suit your needs. Always use sterile, sharp cutting tools when pruning your lemon myrtle, as this reduces the risk of disease.
Common Lemon Myrtle Pests & Diseases
Aphids and spider mites are the most common pests that attack lemon myrtle shrubs. Eliminate them using insecticidal soap or horticultural oils.
Lemon myrtles are susceptible to myrtle rust, a fungal disease that causes purple spots on the leaves. Myrtle rust cannot be cured, so provide your myrtle with ideal growing conditions to reduce the risk of infection.
Lemon Myrtle Care FAQs:
Where Does Lemon Myrtle Grow Best?
Lemon myrtle grows best in Zones 10 and 11 because these shrubs need subtropical climates. Plant lemon myrtles in well-draining soil and provide full sun or partial shade.
What is the Best Way to Propagate Lemon Myrtle?
Lemon myrtle can be propagated either through seed or by cuttings. Both methods are fairly slow, but cuttings are usually the best option.
How Fast Does a Lemon Myrtle Grow?
Lemon myrtles have a moderate growth speed, taking 3 to 4 years to fully mature. Lemon myrtle shrubs grow more slowly in cooler areas.
Lemon myrtle shrubs add fragrance and elegance to subtropical gardens. The leaves are used extensively in cooking thanks to their lemony flavor. For optimal growth, lemon myrtle shrubs require full sun or partial shade and well-draining, slightly acidic soils.
Edd is a budding content writer and gardener living in the United Kingdom. He has a bachelor's degree in Creative and Professional Writing and has written for several gardening publications online. He is passionate about nature and sustainability with a focus on gardening and wildlife.