The story of Lemon Myrtle (Backhousia citriodora)
The Australian Aborigines have been using lemon myrtle in cooking, tea and as a remedy for cuts and abrasions for thousands of years. It is only recently that the medical world has shifted attention to find out more about traditional plant derived medicines particularly the affect on microbial diseases. Studies of Australian traditional plants, such as lemon myrtle have already found some surprising qualities in this area which continue to be the focus of research.
The Lemon Scented Myrtle is a medium sized native tree of the coastal rainforest area between Taree in NSW and Cairns in Qld (from latitude 27deg to 17 deg 30S) in Australia. In the wild, trees grow in a range of altitudes from over 50 to over 700m above sea level. The major centres of distribution are Sunshine Coast and the Mackay area with smaller centres at Miriam Vale, Townsville and Ravenshoe.
Lemon Scented Myrtle is also known by a number of other names, Lemon Scented Backhousia, Lemon Scented Ironwood and Sweet Verbena Myrtle. It is a member of the Myrtaceae family to which the Eucalypts. Tea Tree and many species of the Australian forests also belong. The name "Lemon Myrtle" has been used by growers in New South Wales and Queensland as a marketing and common name for the tree.
The Lemon Myrtle tree was named after James Backhouse, an English botanist, by Baron Ferdinand von Mueller, the great German botanist who was curator of the Melbourne Botanical Gardens in 1853. The tree was first mentioned in 1899 by Joseph H Maiden, Director of the Royal Botanical Gardens in Sydney, in his book "Useful Native Plants of Australia".
The leaf of the B. citriodora was first investigated by Schimmel and Co of Dresden pharmaceutical company over 100 years ago. The company carried out analyses of the lemon oil and noted high (90-97%) citral content.
From the early 1900's, the foliage was harvested from wide stands of trees near Eumundi, north of Nambour in Queensland. The oil distilled from foliage was exported to the United States troops in the Pacific as a as a replacement for lemon essence which was in short supply. In the 1950's some production of oil was carried out in the Maryborough and Miriam Vale areas from bush strands by JR Archibold. In the 1990's there was a revival of Lemon Myrtle with the production of oil and subsequent development of skin products.
How to grow Lemon Myrtle
The Lemon Myrtle is a beautiful small native tree for the home garden. It grows to around 4-6m (12-20") tall and about 2m (6') wide. It is very easy to grow, and likes a position in part shade through to full sun, and a deep rich soil. It does well in most mainland areas of Australia, but needs protection from frost, especially when young.
The tree can be propagated from cuttings which are best taken in November when the plant has new growth. The cuttings should include some wood from the previous year and be around 10 cm in length. Use a good mix of sandy propagation soil and dip in growth hormone to increase the success rate of your cuttings. Keep the cuttings moist during hot weather and do not let the soil get too dry.
When taking cuttings choose a plant that has the best aroma, each myrtle has different genetics so some will be stronger in fragrance than others. Once your cuttings are established you can either plant in fairly rich soil or in a garden pot. This is a rain-forest plant that prefers to have its feet wet and rich soil. I have found that it can take the plants a couple of years to establish in areas with poor soil and low rainfall, the plants need lots of compost and water. Once you have a few plants growing it is not hard to propagate using the layering method.
The leaves are great to have in the garden to make fresh tea, use in cooking or just scrunch between your fingers to enjoy the lemony fragrance.
Researchers at NSW Charles Sturt University found that Lemon Myrtle has very good antibacterial activity and excellent antifungal activity. In fact, studies suggest that Backhousia (Lemon Myrtle) oil has better antibacterial and antifungal properties than the better known tea tree (Melaleuca alternanthera)
Lemon Myrtle oil has strong germicidal powers. In standard tests, Atkinson & Brice were able to demonstrate the antibacterial properties of the Lemon Scented Myrtle (Backhousia citriodora). Tests carried out by researchers on the Germicidal powers indicate that B. citriodora oil had double the rating on Eucalyptus citrodora in controlling Salmonella typhii, the test organism.
Even though the Rideal-Walker test has now been superseded by the Sykes Kesley test, it still remains a valid test. Backhousia has a co-efficient rating of 16 where Eucalyptus citriodora only scores 8. Germicidal properties of Lemon Myrtle have also been proven to be 19.5 times the power of the disinfectant Phenol using the Rideal-Walker test.
Excellent for foodstuffs and medicinal therapeutic purposes; perfumes, food flavourings, confectionary and aromatherapy. The leaves can be used in cooking, or infused and made into a tea.
*Antisepitc, anti-viral, calmative, sedative and corrective
*Australian Medicinal Plant - BACKHOUSIA CITRIODORA: Andrew Pengelly DBN ND MHNAA
Volatility Lemon Myrtle Oil should be stored in a dark glass container in a cool dry storage area or kept under refrigeration. Exposure to sunlight will also lead to oil deterioration. The Lemon Myrtle Oil volatises when heated and so should not be exposed to heat. For convenience and prevention of over use it can be added to other oils. The oil bonds well with vitamin E or vitamin A based products.