Callistemon 'Harkness', Callistemon 'Hannah Ray' and Callistemon 'Dawson River Weeper' are large shrubs growing 4 to 5 m tall. All have an attractive weeping habit.

Callistemon 'Little John' is a dwarf cultivar which produces masses of flowers, and which has blue-green foliage.

Callistemon 'Reeves Pink' and Callistemon 'Mauve Pink' produce attractive pink flowers and grow well near a wall in cold areas and flourish in warmer climates.

What is a Bottlebrush?
Bottlebrushes are members of the genus Callistemon and belong to the family Myrtaceae. They are closely related to paperbark melaleucas, which also have 'bottlebrush' shaped flower spikes. It is difficult to tell to which genus some species belong. Botanists are currently closely studying these plants to determine how they are best classified. There are 34 species currently called Callistemon.
 

Where do they Occur?
Most Bottlebrushes occur in the east and south-east of Australia. Two species occur in the south-west of Western Australia and four species in New Caledonia. Bottlebrushes can be found growing from Australia's tropical north to the temperate south. They often grow in damp or wet conditions such as along creek beds or in areas which are prone to floods.

Bottlebrush Flowers, Fruits and Leaves
The flower spikes of bottlebrushes form in spring and summer and are made up of a number of individual flowers. The pollen of the flower forms on the tip of a long coloured stalk called a filament. It is these filaments which give the flower spike its colour and distinctive 'bottlebrush' shape. The filaments are usually yellow or red, sometimes the pollen also adds a bright yellow flush to the flower spikes. 
Each flower produces a small woody fruit containing hundreds of tiny seeds. These fruits form in clusters along the stem, and are usually held on the plant for many years. The seeds are usually not released from the fruits for several years, but in some species the fruits open after about a year. Fire also stimulates the opening of the fruits in some bottlebrushes.
The new leaves of many bottlebrushes are very ornamental. The leaves are often coloured and, in some species, they are covered with fine, soft hairs.

Bottlebrushes as Garden Plants
Bottlebrushes make excellent garden plants. Plants are all woody shrubs which range from 0.5 m to 4 m tall. The flowers can be spectacular and are irresistible to nectar-feeding birds and insects. Most species are frost tolerant.
The popularity of bottlebrushes as garden plants commenced soon after European settlement and Crimson Bottlebrush (Callistemon citrinus ) was introduced to Britain by Joseph Banks in 1789.
Many species can tolerate (or thrive in) damp conditions, yet most are very hardy and will tolerate drought and limited maintenance. They grow well in a wide variety of soils, except those which are highly alkaline. Plants grown in full sun produce the best flowers.
Plants can be lightly pruned after flowering to keep them in shape. A low-phosphorous fertiliser should be applied in spring and autumn. Mulching will help retain soil moisture and reduce weed growth.
Many cultivars have been selected from natural variants and hybrids between species. Some of these are very good garden plants.

Propagation
Bottlebrushes are easily grown from seed. The unopened fruits should be collected and stored in a warm place in a paper bag until the fine seeds are released. The seed should be sown into a freely draining seed-raising mix during spring and summer.
Bottlebrushes hybridise readily so, if you wish to be sure that you are preserving the features of the parent plant do not grow plants from seed, use cuttings instead. With all cultivars it is essential to propagate from cuttings to retain the form of the parent plant. Cuttings should be taken from semi-mature wood.