Does Bottlebrush Start to Bloom from the Bottom Up?

Bloom Habit

• Some plants, such as common hollyhocks (Alcea rosea), hardy in USDA zones 3 through 9, bloom from the bottom upward, with flowers closest to the base of a stalk opening before those at the stalk's top. Bottlebrush flowers do not fall into that blooming habit category. Flower clusters sometimes appear intermittently throughout the growing season on bottlebrush plants, but clusters located closest to their bases do not open before those on top. Photographs of individual bottlebrush flower clusters, however, show that flowers closest to the tips of the clusters open before those at the base.

Available Varieties

• The available bottlebrush species all have similar flowering traits. Crimson bottlebrush (Callistemon citrinus), hardy in USDA zones 9 through 10, is a 3- to 5-foot-tall shrub with lemon-scented leaves and showy, red flowers. Another red-flowered variety, stiff bottlebrush (Callistemon rigidus), hardy in USDA zones 9 through 10, is 3 to 8 feet tall. Weeping bottlebrush (Callistemon viminalis), hardy in USDA zones 9 through 11, also features red flowers, and its branches have a weeping habit. The bottlebrushlike appearance is most pronounced when all the flowers in a particular cluster have opened to reveal the long stamens.

Culture Requirements

• Purchase bottlebrush shrubs or trees as containerized or "balled and burlapped" nursery specimens. Bottlebrushes require a sunny location in well-drained soil and regular watering until they become established. Thereafter, they can withstand some dry periods. The plants are medium- to fast-growing. As with many flowering plants, bottlebrushes should be pruned after their main flush of blooms, which is generally in summer in cold-winter climates, where the plants are overwintered indoors. Within their native range, where flowering may be intermittent, pruning should take place immediately after the time when the greatest number of flowers appears.

Various Uses

• Although individual bottlebrush flowers open in sequence, they remain open long enough so that the showy "brushes" appear full. Crimson bottlebrush, sometimes called lemon bottlebrush, can be grown as a specimen shrub or trained as a small tree within its hardiness zones. Elsewhere, it can be grown in a large container and displayed on a porch or patio. The same is true for stiff bottlebrush. In general, evergreen bottlebrushes are considered good choices for habitat gardens because their flowers are attractive to hummingbirds. The plants also have been used in groups and planted en masse as flowering hedges.