Callistemon

This group consists of tender, evergreen shrubs and small trees that are natives of Tasmania and Australia. Commonly known as Bottlebrushes, these attractive plants produce spikes of colorful flowers, of which the most conspicuous parts are the tufts of long stamens. These flower spikes resemble bottlebrushes, thus the common name. A. citrinus Splendens is a small tree or medium-sized shrub that produces thick spikes of scarlet flowers. Its slender, leathery leaves give off a lemon scent when crushed. C. salignus can grow up to 8 feet high and wide. Its leaves are narrow and willow-like and its flowers are ordinarily light yellow.

Pot Cultivation

Bottlebrushes can be grown outdoors in mild climates only, in almost any type of soil. When grow in a greenhouse, the temperature shouldn't fall below 45º F. They should be planted in containers filled with rich, porous, peaty soil that has had an abundance of sand added. Repotting is done in the early spring as soon as new growth begins.

Make sure to firm the soil well with a potting stick. Pruning consists of shortening the healthy shoots in half and the weaker ones by two-thirds. This should be done as soon as the flowers have withered. If Bottlebrushes are pruned hard every year, they can be grown in pots that are 6-8 inches, or in larger tubs. They may also be planted in a bed of soil in a conservatory where they'll grow from 8-10 feet tall. These plants require full sun in order to develop the flower buds, so they can be placed outside in the summer.

Propagation

Seeds can be sown in pots of sandy peat in April. Firm shoots can also be inserted into pots that are filled with the same compost. Place them under a bell jar in the greenhouse in July or August. When they've formed roots, pot them in 3-inch pots and later, into larger ones. Prune the main shoot in half and the following side branches to encourage bushy growth.