Manuka in New Zealand grows as a small, creeping shrub, or a tree up to 8m tall. Most widely known as Manuka, its botanic name is Leptospermum scoparium. It can also be commonly referred to as Red Manuka, Kahikatoa or Tea Tree. However, this should not to be confused with Australian Tea Tree (Melaleuca alternifolia) and another common New Zealand tree that looks very similar and is easily mistaken for Manuka, called Kanuka (White Manuka, Kunzea ericoides).
Manuka is a hardy woody shrub found throughout most of New Zealand, from lowlands to sub-alpine areas (up to an elevation of 1370m)1. Manuka is a natural land remediation species as it rapidly colonises exposed soil making it useful in the initial stages of re-vegetation in lieu of the re-establishment of native forests. It is often found to be the dominant species on exposed sites that are prone to wind and salt, or on soil that is too wet or dry, or too infertile for other forest species.2
Manuka has value beyond that of its historical uses. Manuka's economic value dates back as far as the 1771's when Caption Cook and the Endeavour arrived back in England carrying seeds of many indigenous species.3 By 1778 seeds he took from New Zealand were being offered for sale as plants by nurserymen in England. Today, Manuka has economic value due to the unique antimicrobial properties of both its honey and essential oil. Much research is focused on utilizing these properties for natural, functional products.
Manuka has a long history of internal and external medicinal uses by the indigenous Maori people of New Zealand, as well as the early European settlers. Maori have used all parts and by-products of this tree; bark, leaves, roots, smoke, ash, flowers, berries, resin... in their own right, or mixed with other native plant species for a vast range of aliments.4–6,6–11
- the hard red Manuka wood for paddles, spades, spears and houses;
- the bark to create water containers and to waterproof their roofs;
- an infusion of the bark externally and internally as a sedative, for scalds and burns;
- the ash from the bark rubbed onto the skin to treat skin diseases;
- the inner bark was boiled and the liquid used as a mouthwash;
- the thick roots, hardened in a fire, for clubbing seals;
- white smoke produced by burning dried brush to drive off insects;
- fresh leaves to make an aromatic bitter tea;
- the vapour from leaves boiled in water was used for colds.
Since the early visits of Caption Cook to New Zealand (1769–1777), and the following sailors and subsequent settlers, many enjoyed Manuka leaves as a substitute for English tea (giving to the English name Tea Tree). Unsurprisingly early European settlers also became aware of the healing properties of Manuka as used in Maori medicine (Rongoa). Many adopted and experimented with it for curing their own common aliments too.
Manuka and other native plants and their historical use, has been well documented1–8 and continue to be used, taught and studied within New Zealand.
The essential oil extracted from leaf and twig (aerial) parts of the tree via steam distillation also has unique antimicrobial properties that vary greatly depending on the location of trees. The properties of this oil – predominantly from the East Cape region of the North Island of New Zealand – have been well researched and continue to be of interest.
This website introduces the science behind the oil and allows you to know more about the quality of the oil you buy.