Scientific: Melaleuca viminalis (Synonym: Callistemon viminalis)
A scientific name quagmire: Lyn Craven of the Australian National Herbarium [Novon 16 468-475; December 2006 “New Combinations in Melaleuca for Australian Species of Callistemon (Myrtaceae)”] argued based on genomic research that the differences between the two genera, Callistemon and Melaleuca, are insufficient to warrant them being retained separately and that they should be combined, thus Melaleuca is the preferred genus based on earlier precendence. Thus, I prefer to use the genus Melaleuca instead of Callistemon for this wonderful landscape taxon.
Common: weeping bottlebrush
Family: Myrtaceae
Origin: Northeast coastal Australia, primarily Queensland, with a small disjunct population in western Australia.
Pronounciation: Mel-a-LOU-ka vi-mi-NAL-is
Hardiness zones:
Sunset 12-24, cold damage in zone 8-9
USDA 8 (with cold protection), 9-11
Landscape Use: Weeping bottlebrush usually best used as a vertical accent tree or focal point. Also good for use around water features where a pendulous upright element is needed. Dwarf cultivars are smaller shrubs used in landscape borders as edging plants or in container pots.
Form & Character: Upright, ranging from a small and diminutive prostrate shrub to a weeping and graceful, medium-sized tree.
Growth Habit: Evergreen, woody, perennial broadleaf shrub to large tree of highly variable size and form. Ultimate size ranges from a small shrub to a moderately-growing large tree to 50-feet tall at maturity. Popular dwarf cultivars as landscape shrubs are slow growing, low and prostrate to only 2-feet tall with equal to slighter greater spread.
Foliage/Texture: Young leaves reddish, pubescent, mature leaves elliptical to lanceolate nearly sessile, aromatic; medium texture (dwarf cultivars) to medium fine texture (standard plants).
Flowers & Fruits: Red bottle brush flowers (stamens tower above with protruding bright red filaments with sometimes yellow anthers) followed by persistent small round nut-like fruit.
Seasonal Color: Striking display of red flowers during Spring.
Temperature: Tolerant to 20oF, but suffers at bit if temperatures are above 112oF for an extended period of time.
Light: Full sun
Soil: Well-drained soils preferred, but tolerant of most soil textures including those that are of alkaline and/or clay composition. However, dwarf cultivars are more prone to chlorosis in Phoenix soils than upright standard forms. Overall, weeping bottlebrush is less prone to show yellow leaf chlorosis in Phoenix than its 'little brother', Melaleuca citrina.
Watering: Infrequently water deeply during the summer.
Pruning: Train rigorously when young to attain upright form and remove crossing branches, elsewise raise the crown base as needed in order to train into a form that resembles a tree. Pruning is best done in mid to later spring after flowering.
Propagation: Seed propagation is somewhat difficult with variable outcomes, whereas semi-hardwood cutting propagation is relatively easy and consistent.
Disease and Pests: None that are significant in the Phoenix area.
Additional comments: Weeping bottle brush is the best acclimated of the former Callistemon species to the harsh environment of the Phoenix area. The red bottle brush flowers strongly attract bees and to a lesser extent, hummingbirds.
Locally common cultivars that make excellent low maintenance accent plants include:
