Thirty-four species of bottle brush trees and shrubs exist. Bottle brush are widely grown in the Western United States landscape and a favorite in Southern California landscapes. The cold hardiness zones put forth by the U.S. Department of Agriculture (USDA) are based on winter lows only. When you purchase a plant, the label usually states the zone in which it can survive: the coldest winter temperature of that area.
Growing Bottle Brush Trees and Shrubs
Bottle brush, a native to Australia, is an easy-to-care-for, fast-growing, evergreen shrub or tree bearing colorful flowers.
Zones, in this article, refers to the Sunset climate zones. These zones, put forth by Sunset publishers, are based on year-round temperatures of highs, lows, rainfall, and humidity; not just winter lows. Check the Sunset Western Garden Book to learn how to grow bottle brush in the Western United States.
Stiff Bottle Brush (rigidus)
Stiff bottle brush tree or shrub reaches 20 feet tall and 10 feet wide. The sharp, pointed leaves and sparseness of the plant make it the least graceful of all the bottle brush species. Red flowers bloom in spring and summer reaching 2 1/2 to 4 1/2 inches in length. Stiff bottle brush produces prominent seed capsules. It does best in zones 8, 9, and 12 to 24.
White Bottle Brush (salignus)
White bottle brush grows 20 to 25 feet tall and 10 to 15 feet wide. It forms a dense crown of foliage. New growth appears as bright pink to copper in color. The willow-like leaves grow 2 to 3 inches long. The pale yellow to cream-colored flowers form 1 1/2 to 3 inch clusters in spring and early summer. It can be trained as a small tree or hedge. For hedges, plant bottle brush 4 to 5 feet apart. White bottle brush does best in zones 8, 9, and 12 to 24.
Tree or Shrub Weeping Bottle Brush (viminalis)
Weeping bottle brush reaches 20 to 30 feet tall with a 15 foot spread. The 6 inch leaves are narrow and long. It blooms bright red brushes from late spring to summer; there are scattered periods of bloom throughout the rest of the year. Weeping bottle brush doesn't do well in windy, dry areas. The trees need staking and thinning to prevent tangled, top-heavy growth. The leaves grow toward the ends of long hanging brushes. Weeping bottle brush does best in zones 6 to 9 and 12 to 24.
Lemon Bottle Brush (callistemon citrinus)
Lemon bottle brush tree or shrub, named for its lemony smelling leaves, tolerates heat, cold and poor soil better than any of the other species. The massive shrub stands 10 to 15 feet tall and wide. Train lemon bottle brush into a tree when it is young by staking and pruning it. The tree grows 20 to 25 feet tall. Damage may occur in this species when temperature drops to 20 degrees Fahrenheit. Bright red six-inch brushes appear throughout the year. Due to its drought tolerance, lemon bottle brush is a favorite in many desert-home landscapes. It does best in zones 8 and 9.
Propagation of Bottle Brush Trees and Shrubs
Bottle brush may be grown from seed, but if you wish to retain the appearance of the parent plant you must use cuttings instead. Take the cuttings from semi-mature wood. When growing bottle brush from seed, collect the fruits of the tree and store in a paper bag until the fruits pop open, revealing the seeds. Sow seeds in pots and a seed-starting potting mix, available at any gardening center. Transfer seedlings outside in spring after all danger of frost. If growing from cuttings, plant in a cutting medium available at garden centers. Transplant outside as you would seedlings.