Weeping Bottlebrush (Callistemon viminalis)
Also called red bottlebrush, this tree has dramatically red flowers and relatively low water needs compared to other ornamentals. If you’re looking for more color pop, it’s a great alternative to a willow acacia.
Mature Canopy Size
15–25 ft tall, 10–20 ft wide; naturally forms a fountain-like, weeping canopy
Growth Rate
Moderate — 1–2 ft per year with irrigation
Water Requirements (Minimum vs. Maximum Growth)
Minimum: Moderate — needs deep irrigation every 10–14 days in summer to survive
For Maximum Growth & Bloom: Weekly irrigation encourages lush foliage and heavy flower production
Ecological & Functional Benefits
Showy red “bottlebrush” flowers attract hummingbirds, bees, and butterflies
Evergreen, providing year-round screening and color
Graceful weeping form makes it an excellent focal tree
Edible / Harvest Season / Nutritional Benefits
Not edible — flowers are ornamental only, though nectar attracts wildlife
Minimum Chill Hours
None — subtropical species, frost-sensitive below ~25°F
Maintenance Requirements
Moderate — prune lightly after bloom cycles to shape and prevent legginess
Generally clean tree, but can drop flowers in spring flush
Thorny or Not?
No
Deciduous or Not?
Evergreen in Phoenix with proper irrigation and frost protection
Root System
Moderately spreading roots, not typically destructive
Safe near patios, walls, or pools if given 10+ ft spacing
Benefits from deep, consistent watering to keep roots stable in desert soils
Native Range
Native to eastern Australia, where it grows along riverbanks and wetlands. Widely cultivated in arid and subtropical regions as an ornamental.
Miscellaneous Notes
Heavy bloom season in spring, with sporadic flowers year-round in Phoenix
Best in full sun with protection from extreme reflected heat
Works well as a single centerpiece tree, group planting, or even trained into hedge form
Dwarf varieties (Callistemon citrinus ‘Little John’) available for smaller spaces
Questions about the Weeping Bottlebrush?
Comment below or on our social media pages @permascaping.
