Callistemon salignus White - Bottlebrush

Callistemon salignus, recently classified under the genus Melaleuca, is an Australian bush that is very accommodating, hardy down to -7°C (19.4 °F), tolerant of both occasionally dry and poor soils as well as waterlogged ones. It forms a cluster of arching stems, covered in long lanceolate leaves and numerous white flowers that resemble small bottle brushes, from spring to autumn. It is best grown in the ground in mild, oceanic or Mediterranean climates. However, it also thrives in large pots and can be overwintered anywhere else.

Native to the southern coasts of Australia and Tasmania, the Melaleuca can be found on marshy and windswept heathlands, up to 1500m (4921ft) altitude. The name Melaleuca comes from the Greek words for black and white, describing its dark trunk and white branches. It belongs to the myrtle family, just like its Australian cousins Leptospermum and Eucalyptus, and its Mediterranean relatives Myrtus. It naturally grows in mild, oceanic climates, as well as occasionally dry areas, usually on mineral-poor, leached, rather acidic soil with a limestone subsoil. The essential oil of Niaouli is produced from Melaleuca.

Callistemon salignus is a ramified bush that can reach up to 1.50m (4ft 11in) in height and 4m (13ft 1in) in width at maturity, sometimes more in optimal conditions in the ground. This bush has trailing branches and long aromatic leaves that are alternately arranged. Their colour ranges from bluish-green to greyish-green. The juvenile foliage is a pretty pink-red. The slightly fragrant flowers, which are nectar-rich and attractive to bees, appear from May to July, although this can vary considerably depending on the climate. The flowers are composed of long white stamens and are grouped in 4 to 10 spikes that resemble bottle brushes at the tips of the branches. They produce woody capsules, embedded in the bark, containing seeds that take one to two years to mature. This bush can be lightly pruned after flowering, from May to July.

Once established, Callistemon salignus adapts to almost any type of soil, even limestone, waterlogged or dry in summer. It can withstand temperatures as low as -7°C (19.4 °F), but the above-ground parts may be damaged at -5°C (23 °F). It should be planted in a sheltered location, in full sun but not in excessively hot conditions. It tolerates sea spray well, making it a beautiful addition to mixed hedges (of moderate size) in coastal gardens. It can be planted as a specimen or in mass plantings, alongside Grevillea, Leptospermum, and other plants. It can also be used in the creation of an evergreen hedge, alongside Myrtus, evergreen Ceanothus, large Cistus (Cistus laurifolius, Cistus x aguilari), Feijoa, Oleander, and other lavender species. In regions with very cold winters, the plant should be grown in a pot and protected from frost throughout the winter.