Melaleuca gibbosa

Melaleuca gibbosa, also known as Cajeput Tree, is perhaps better known as Niaouli, a name that encompasses all the bushes of the Melaleuca genus. This is a small Australian bush that is very accommodating, hardy to at least -7°C (19.4°F), tolerant of occasionally dry and poor soils as well as waterlogged ones. It forms a bunch of arched stems, covered with aromatic foliage, where numerous purple flowers resembling small bottle brushes bloom from spring to autumn and sometimes throughout the year depending on the region. Its cultivation in the ground is reserved for mild, oceanic, or Mediterranean climates. However, it adapts very well to container cultivation, to be stored indoors during winter elsewhere.

Native to the southern coasts of Australia and Tasmania, Melaleuca gibbosa sprinkles swampy heathlands and windswept areas up to 1500m (4921ft) altitude. The name of the Melaleuca genus is derived from Greek, meaning black and white, characterising its dark bark at the trunk level and white at the branch level. Its species name, gibbosa, meaning "hunchbacked," refers to the lumpy appearance of its branches covered with fruits sunken into their bark. It belongs to the Myrtaceae family, just like its Australian cousins Leptospermum and Eucalyptus, and its Mediterranean relatives Myrtus.

It grows naturally in regions with a mild oceanic climate, as well as in intermittently dry areas, mostly on mineral-poor, leached, rather acidic soil but on limestone substrates. It forms a small, dense, ramified bush, reaching a height of 1m (3ft) and a width of 1.2m (4ft), with a rather fast growth rate. This bush with trailing branches bears small aromatic leaves that are alternate, ovate to obovate, arranged in opposite pairs, with each pair of leaves inserted at a right angle to the next one. Their colour ranges from bluish-green to greyish-green. The slightly fragrant, honey-bearing and nectar-bearing flowers appear at different times of the year, as this plant adapts to the climate and soil it encounters. The flowers are composed of long purple stamens that turn white as they fade. They are grouped in spikes of 4 to 10, taking the form of small bottle brushes at the end of the branches. They produce woody capsules, sunken into the bark, containing seeds that take one to two years to mature. This bush can be lightly pruned after flowering, from May to July.

The Cajeput Tree adapts to almost all soils, even limestone ones, waterlogged or dry in summer. It can withstand frosts of around -8°C (17.6°F), but the aboveground parts can be damaged from -5°C (23°F). It should be placed in a sheltered spot, in full sun but not a scorching position. It tolerates sea spray well, making it a beautiful small hedge bush for coastal gardens. It is cultivated and used like Callistemons: it can be planted as a standalone or in groups, with Grevilleas, Leptospermums, and Callistemons. It can also be used to create an evergreen hedge alongside Myrtles, evergreen ceanothuses, large cistuses (Cistus laurifolius, Cistus x aguilari), Feijoa, Rose Laurels, and lavenders. In regions with very cold winters, the plant should be grown in a pot and protected from frost throughout the winter.