Melaleuca alternifolia

The Tea Tree is presumably named for the brown coloration of many water courses caused by leaves shed from these trees. It is a gorgeous evergreen shrub or small bushy tree, growing to 15-20 ft has narrow linear leaves, highly aromatic when rubbed. The plant is very slow growing and can be kept as a bush for many years. Profuse white flowers are borne from late spring to mid-summer.

After Eucalyptus, this is the most famous of all Australia plants. Melaleuca alternifolia is notable for its essential oil, which is both anti-fungal, and antibiotic. It is produced on a commercial scale, obtained by steam distillation of the leaves, and marketed as Tea Tree Oil.

There is a very long history of its use in aromatherapy. The native Australian inhabitants used the therapeutic oil of this tree for a wide range of topical applications. They crushed the leaves to use as rubbing mediums and even bathed in the water that had collected under the trees. The use of Tea Tree oil remained confined to Australia, as a bush remedy, until 20th Century. Only in 1922 an Australian chemist Arthur Penfold distilled this oil and published a paperabout its wide-ranging antibacterial and antifungal activity. It was announced to the world that this was a new type of germicide, gentle to skin cells but harmful to the invading germs and successfully used to treat infections and infestations. During the Second World War Tea Tree Oil was in such short supply that all the available stocks were used to help stop infections from war wounds in soldiers. However, after the war, it was deemed necessary that a cheaper, more readily available antimicrobial alternative should be manufactured, and the once thriving industry went into a steep decline.

Only in the 1990s, a scientific research team lead by Professor Tom Riley at the University of Western Australia, continued to promote the effectiveness of this ancient and valuable oil. Melaleuca oil was found to be invaluable as a topical disinfectant for treating a staphylococcus strain that had evolved to beat most of the synthesized antibacterial medicines (antibiotics) available from orthodox medicine. Tea tree oil has been used as complementary therapy in surgery, burn care, and dental care. Numerous body care products are available, including soap, shampoo, toothpaste, lip balm, topical cream, and essential oil.

This valuable plant is pretty easy to grow. It requires a fertile, well-drained moisture retentive lime-free soil and a full sun. Marginally frost hardy, it succeeds best in a warm climate. It makes good hedge or screening plant. The leaves when crushed smell wonderful: a mix of lemon scent and a fresh forest strawberry.

Propagation by seeds only, which is not always successful. For successful germination, seeds must be kept in slightly moist medium with good drainage, and only slightly covered by the mix. Bright light and warm temperature is a must for germination. This plant is very rare in collectors gardens, especially bigger specimens.

Melaleuca armillaris

It is a hardy, commonly grown species, often used as a fast-growing screen plant. In its natural state, it grows on coastal cliffs and along estuaries.

The flowers are white, sometimes cream-coloured, rarely pink, and are arranged in cylindrical spikes on the sides of branches, often on older wood.

Melaleuca cajuputi, Melaleuca leucadendron

Evergreen shrub or usually single-stemmed tree with an extensive root system, sometimes with aerial adventitious roots. Bark layered, fibrous and papery, grey to white.

Within the complex, M. cajuputi is most closely related to M. viridiflora and M. quinquenervia. M. quinquenervia is like M. cajuputi but its old leaves are not conspicuously dotted with glands, not thin-textured and have obscure reticulations.

Melaleuca citrina, Callistemon citrinus, Callistemon lanceolatus

Melaleuca cuticularis, Melaleuca abietina

The branches of the plant are rigid and tortuous and the leaves linear to oblong, up to 1cm long and dark green in color. Stems and trunk are clad in a pale papery bark which contrasts well with the foliage. Judicious pruning should be carried out to expose the trunk and lower branches so that this feature can be accentuated. The cream flowers, in brushes, are borne at the ends of the branches.

In cultivation it seems to be adaptable to a few soil types but mainly prefers slightly heavy, moist soils. It needs protection from wind and seems to prefer full sunlight. Newly growing tips have been observed to be slightly burnt by frost, but otherwise the species is frost hardy.

Melaleuca decussata

This is a quick-growing small multi-stemmed shrub with upright stems and slightly pendulous branch tips. Small leaves are arranged in two pairs of opposite rows forming a cross when viewed from above. Mauve flowers are carried in small, cylindrical spikes on short, lateral branches or at the base of leafy branches.

Melaleuca elliptica

Melaleuca elliptica is a shrub with pale grey, papery bark that peels in thin strips. Its leaves are arranged in alternating pairs (decussate), each pair at right angles to the ones above and below so that there are four rows of leaves along the stems. The leaves are elliptic to egg-shaped with the ends usually rounded.

Melaleuca elliptica can withstand salt winds in dry coastal areas and makes a good screen against salt spray. It is drought and frost hardy to about 20 degrees F. once established and can hold up to salt laden winds along the coast, making it a good first exposure screen to protect other plants in beachside plantings.

Melaleuca ericifolia

Yellow or creamy white flowers that look like small bottle brushes. Dark green linear (needle-like) leaves. White bark that peels off in strips as the tree grows. Tolerances: Drought; poor drainage; any soil; salt air; gusty winds; fog. Special Considerations: Prefers sun. When planting, handle rootball with care or tree will go into transplant shock. Do not let rootball dry out during establishment period. Needs extra water in hot or windy conditions. Melaleuca ericifola - An essential oil with antiseptic and calming properties. This variety of melaleuca oil is exceptionally gentle and non-irritating to the skin and is used by the well-known essential oil.

Melaleuca huegelii

Melaleuca quinquenervia

In contrast with its relative, a valuable Tea Tree, this Melaleuca has rather disturbing story. Being a tough plant, tolerating both standing water or dry upland situations, Melaleuca quinquenervia was introduced in Hawaii and the Florida Everglades, in order to help drain low-lying swampy areas. It has since gone on to become an invasive weed with potentially very serious consequences being that the plants are highly flammable and spread aggressively.

Melaleuca quinquenervia is an evergreen tree with a slender crown and drooping branches. Melaleuca grows very fast, up to 6 ft per year, and produces dense stands that completely shade out all other vegetation. It usually gets about 40 ft tall, but can get up to 100 ft if conditions are favorable. The bark is whitish and spongy, peeling off in thin layers. The leaves smell like camphor when bruised. The flowers are creamy white and arranged in "bottle brush" spikes; they are followed by fruit - small woody capsules, each containing several hundred tiny seeds, dispersed then by wind and water. A single tree that starts blooming when two year old, can produce 20 million seeds per year. The seeds are stored until some form of stress, such as frost, fire or human- induced injury, including herbicide, causes the capsules to open. The plant re-sprouts from cut stumps and from roots of fire-killed trees. Mature melaleuca trees survived Florida record-breaking freezes. Freezing is yet another environmental stress factor known to trigger mass seed release.

In Southern Florida, Melaleuca occupies now several million acres, primarily within the Everglades system. Its populations have nearly quadrupled over the past decade, it has become one of the state's worst invasive weeds and represents a severe threat to the integrity of the Florida Everglades. Melaleuca was introduced into Florida in 1906 as an ornamental and widely planted for landscaping and for "swamp drying." Seeds were scattered from airplanes over the Everglades in the 1930's in an attempt to create forests and drain the swamp. Even as late as the 1960's, Melaleuca was still being recommended as an ornamental. Today, state and federal agencies are actively working to control the spread of this exotic menace. Biological control agents from Australia have been released. Crews are at work continuously cutting and herbiciding melaleuca trees in state parks, Everglades National Park and Big Cypress National Preserve.

Melaleuca quinquenervia is similar to Melaleuca cajuputi but its old leaves are not conspicuously dotted with glands, not thin-textured and have obscure reticulations.