Family: Myrtaceae
Common Name: Bottlebrush

Although native to Australia, so many callistemons are grown in California that many Americans think they are native to their country. They are, in fact, the true bottle-brushes. Callistemons are showy shrubs and trees, grown now in many parts of the world as ornamentals and street trees, and as greenhouse plants in frosty areas. They are easily cultivated, and are favored by nectar-and pollen-feeding birds. Most species flower twice a year, in spring to early summer and more lightly in autumn. Numerous species are available in the US and among the most popular are C. citrinus and its cultivars, C. linearis, C. rigidus, C. salignus and C. viminalis and its cultivars.

Species

C. acuminatus is a windresistant plant, with crimson brushes, suitable for coastal gardens. It grows to 3 m (10 ft).

C. brachyandrus can tolerate dry conditions and grows to 2.5 m (8 ft). It has needle-like foliage and red brushes with yellow tips.

C. citrinus, zone 8, a hardy, vigorous species, with red brushes, was one of the first callistemons to be cultivated. Despite its name, the foliage has more of a eucalyptus oil fragrance than a citrus aroma. There are a number of cultivars including 'Burgundy', with deep red, summer brushes; 'Mauve Mist', with mauve brushes; 'Candy Pink', with deep pink, summer brushes; 'Endeavour', with large red brushes; 'Reeves Pink', a small, 2 m (6 ft) shrub with soft pink brushes; and 'Red Clusters', which grows to only 1 m (3 ft), with clusters of late summer, red brushes (a white form is also available).

C. linearis, zone 8, has masses of fine, bronze-red flower spikes and stiff, narrow leaves. It grows to about 3 m (10 ft).

C. macropunctatus has scarlet, gold-tipped flowers and grows to 3 m (10 ft). A deep red form is also available.

C. pallidus, from New South Wales, Victoria, Tasmania and South Australia, grows well in cold areas.

C. paludosus has creamy to pale pinkish flowers and grows 3 m (10 ft).

C. phoeniceus, fiery bottlebrush, from Western Australia, has dazzling scarlet brushes and thick, rather glossy leaves. It grows to 3 m (10 ft).

C. pinifolius, a native of the Sydney region, grows to 2 m (6 ft), with fine foliage and red flowers.

C. salignus, zone 8, is tree-like, growing 8-12 m (26-40 ft), and can withstand very wet conditions. The new foliage growth is flushed with pink, while the mature brushes are creamy white. It flowers in spring. There is also a red form.

C. shiressii grows to 4 m (13 ft), with cream brushes in spring.

C. sieberi, zone 7, native to alpine areas of Australia, has pale yellow brushes and fine foliage. A late flowering shrub, with lovely pink bud bracts, it grows 2 m (6 ft).

C. speciosus, showy bottlebrush from Western Australia, has the largest, deep red brushes of the species and grows 2-3 m (6-10 ft).

C. viminalis is a very hardy species from coastal Queensland and northern New South Wales, with graceful weeping foliage and red brushes. It grows to 8 m (26 It). Cultivar 'Captain Cook' is a very good form, growing to 2 m (6 ft) and flowering profusely over a long period. It has red brushes. 'Hannah Ray', with scarlet brushes, grows to 4 m (13 ft).

C. viridiflorus has yellowish green brushes in summer and grows to 2 m (6 ft).

Cultivation

In areas prone to frosts, grow the tender and half-hardy species in a cool greenhouse or conservatory, in pots of soil-based potting compost. Provide light and airy conditions. Outdoors, grow in acid to neutral soil. Although callistemons are adaptable, they prefer a moist, well-drained position. Mature trees should never be transplanted. Propagate from seed contained in the woody capsules borne along the stems. Place capsules on a tray or in a paper bag in a warm place to release the fine seed. Sow on light, sandy soil, and barely cover. Callistemons can also be propagated from tip cuttings taken in spring or, more easily, in autumn. Place in a 3:1 sharp sand and peat mix and keep moist. Most callistemons are free from garden pests. After flowering, prune back most of the spent blossoms to discourage woodiness and to ensure vigorous new flowering in the following season.

Climate

Zone 9 for most.