Growing Callistemon – Callistemon (or Bottlebrush) is an excellent choice if you want a ‘novelty’ plant, and it is also a good one to pick if you want an easy-to-grow specimen which blooms in summer. With their vibrant, fuzzy-looking flowerheads in summer, Callistemon are instantly recognisable plant. Callistemon are evergreen shrubs with aromatic, linear to lance-shaped leaves and bottlebrush-like spikes of flowers in which the long colourful stamens are prominent.
Callistemon is native to Australia mostly growing in moist soil in open or woodland sites. It does not mind dry air – all it needs is a sunny spot, cool conditions in winter and a good soaking in spring and summer.
Callistemon citrinus will reach about 3 ft high and in summer the cylindrical flower-spikes appear – no petals, just yellow-tipped red stamens. Leaves bronzy when young.
Callistemon linearis is a bushy, medium-sized shrub with linear leaves and red bottlebrush spikes up to 12cm long. Leaves are aromatic when crushed.
Callistemon pallidus (Lemon Bottlebrush) is an erect or spreading evergreen shrub, 2-4m high, with numerous slender branches. The young shoots are silvery or red and covered in silky hairs, as well as narrowly-elliptic, grey-green or dark green, leaves up to 10cm long. Cream or pale yellow flowers, in semi-open ‘bottlebrush’ spikes 10cm long, appear from late spring to midsummer, followed by woody fruit capsules which may persist for several years.
Secrets of success
Temperature: Average warmth – minimum 45°F in winter.
Light: As much light as possible. Shade from hot sun.
Water: Water liberally from spring to late fall. Water sparingly in winter.
Air humidity: Misting is not necessary.
Callistemon viridiflorus ‘Xera Compact’
Planting: Outdoors, Callistemon look more comfortable in shrubs or mixed borders if associated with Mediterranean plants also possessing drought tolerant foliage – these include salvias, hebes, caryopteris and rosemary. They also look nice with flamboyant woody plants such as yucca, palms and tetrapanax.
Pruning: Prune in early spring and stand the pot outdoors in summer.
Propagation: Take stem cuttings in spring. Use a rooting hormone and provide bottom heat. Sow seeds in spring.