Callistemon citrinus: Discover the Vibrant Crimson Bottlebrush

Callistemon citrinus (Scarlet Bottlebrush)
Callistemon citrinus (Scarlet Bottlebrush). Source
Botanic nameCallistemon citrinus
Other namesCrimson bottlebrush
Main OriginEast and southeast coast of Australia
Mature size2 – 3 m x 3 – 4 m (w x h)
Mature formShrub or small tree with an open or dense canopy
FoliageNarrow, elliptical, mid, dark or grey-green
Growth rateModerate to fast
PositionFull sun, light shade
SoilAdapts to most soils
WaterMinimal, deep watering during the establishment
ClimateMediterranean, temperate, subtropical
FlowerBright red, cylindrical spikes in spring and summer
UseFeature specimen, hedge, screening
NotesTolerant of wet conditions, suitable for coastal sites

Overview

Callistemon citrinus, commonly known as the Crimson Bottlebrush, stands out for its bold, striking red flower spikes and ability to thrive in tough conditions. Fast-growing and highly adaptable, this Australian native is a favourite for hedges, screens, and wildlife-friendly gardens.

It blooms profusely through spring and summer, attracting birds and pollinators while adding a vibrant burst of colour to the landscape.

With its dense form, evergreen foliage, and low-maintenance nature, Callistemon citrinus offers both beauty and practicality, making it an excellent choice for gardeners who want colour, structure, and reliability in one plant.

Callistemon citrinus (Scarlet Bottlebrush) flowers
Callistemon citrinus (Scarlet Bottlebrush) flowers.

Origin and distribution

Callistemon citrinus is native to the temperate and subtropical regions of eastern Australia. It’s commonly found along creek lines and in floodplains, swamps, and shrublands, often in areas that experience seasonal wetness followed by extended dryness.

These natural conditions have shaped its strong adaptability, allowing it to thrive in both wet and dry conditions and giving it a reputation as one of the most reliable natives for varied climates.

Callistemon citrinus has also been widely cultivated in Australia and abroad, especially in regions with Mediterranean-style climates. It’s now a familiar presence in streetscapes, public parks, and home gardens worldwide, celebrated for its resilience, striking appearance, and ecological benefits.

Callistemon citrinus main distribution
Callistemon citrinus main distribution. Reference

Growth and care

One of the reasons Callistemon citrinus remains a favourite in home gardens and public landscapes is its impressive tolerance of tough growing conditions. It performs best in full sun, but will grow in light shade.

In the wild, Callistemon citrinus grows across regions of eastern Australia that experience a temperate to subtropical climate. These areas typically have warm to hot summers, mild to cool winters, and seasonal rainfall.

The species can be found in diverse habitats, often associated with periodic wetness or waterlogging. However, the plant is naturally adapted to fluctuating moisture levels and copes with prolonged periods of dryness exceptionally well.

It grows in various soils, including well-drained, poorly drained, and even heavy clay or compact soils. By and large, Callistemon citrinus thrives best in fertile, heavier, slightly acidic to neutral soils with adequate drainage.

Callistemon citrinus (Scarlet Bottlebrush) blossom
Callistemon citrinus (Scarlet Bottlebrush) blossom. Source

The plant is generally considered frost-tolerant. It is highly suitable for cool temperate regions. However, heavy and prolonged frost can still damage younger plants and reduce lushness and blooming in older plants.

The species is also salt-tolerant and can handle moderate coastal exposure. Although it is not the first-line coastal plant, it tolerates salt spray, salty winds and soil salinity, making it ideal for seaside gardens.

Callistemon citrinus is a low-maintenance plant that rewards minimal care with lush growth and vibrant flowering. Regular deep watering will help young plants develop a strong root system. Apply mulch around the base to conserve moisture. Once established, it’s remarkably tough.

While Callistemon citrinus can grow in nutrient-poor soils, it will benefit from an annual application of balanced fertiliser and organic matter, ideally in early spring before new growth begins.

Light pruning after flowering encourages a bushier habit and more blooms in the following season. Regular trimming helps maintain shape for hedging or screening.

Callistemon citrinus (Scarlet Bottlebrush) profuse blooms
Callistemon citrinus (Scarlet Bottlebrush) profuse blooms.

Features

The original Callistemon citrinus plant is celebrated for its bold crimson flower spikes, which burst into colour primarily during spring and summer, with occasional flushes in autumn. The cultivars also bring a wealth of other colours, such as white, pink and salmon.

These vibrant, brush-like blooms are rich in nectar and highly attractive to native birds, bees, and butterflies, making the plant both a visual and ecological asset in any garden.

Unlike its cousin, Callistemon viminalis (Weeping Bottlebrush), Callistemon citrinus is more rigid and upright, with stiffer foliage. It often grows into a large, dense shrub but can develop as a small tree with a broad, rounded canopy, reaching 3 – 4 metres tall.

Its narrowly elliptical, rigid leaves often appear dark or grey-green. They emit a pleasant citrus-like aroma when crushed. After flowering, the plant produces woody seed capsules that persist along the stems, adding texture and interest to the plant.

Callitemon and Eastern Rosella
Callitemon citrinus and Eastern Rosellas. Source

Main varieties

Small

  • Firebrand: A low-spreading, compact shrub highly useful for border or low boundary planting, featuring vibrant red-pink flower spikes, reaching 50 cm tall.
  • White Anzac: A low-spreading shrub featuring white bottlebrush flowers, often pruned for low boundary hedges due to a straggly habit, reaching 1 – 1.5 metres in height.
  • Neon Pink: An upright, compact variety featuring profuse bright, fluffy pink flowers, growing 1.5 metres tall.
  • Demesne Rowena: A cross between ‘White Anzac’ and ‘Splendens’, featuring red flowers upon opening, later turning deep pink, growing 1.5 – 2 metres tall.
  • Hot Pink: A compact hybrid between Callistemon citrinus and Callistemon pallidus, featuring large deep pink flower spikes, reaching 1.5 – 2 metres tall.
Callistemon citrinus (Crimson Bottlebrush)
Callistemon citrinus (Crimson Bottlebrush) flowers.

Medium

  • Endeavour (syn. Splendens): A vigorous, compact variety featuring stunning, large, bright crimson flower spikes and bronzy new growth, growing 2 – 3 metres tall.
  • Pink Champagne: A popular cultivar featuring soft pink or light pink bottlebrush flowers and silvery-olive new growth, reaching 3 metres tall.
  • Reeves Pink: A tough, vigorous variety featuring profuse eye-catching bright pink flower spikes, growing 3 metres tall.
  • Burgundy: A fast-growing variety featuring unusual pinkish new growth and large, maroon to burgundy flower spikes, reaching 3 metres tall.
  • Western Glory: A hardy cultivar featuring abundant rose-pink bottlebrush flowers, often pruned to a smaller size as a hedge or screen, reaching 3 metres in height.
Callistemon citrinus 'Splendens'
Callistemon citrinus ‘Splendens’. Source

Large

  • Candy Pink: A hardy cultivar featuring soft salmon pink flower spikes, often pruned back to semi-hardwood to encourage a dense habit, reaching 4 metres tall.
  • Mauve Mist: A striking, hardy cultivar featuring vivid mauve bottlebrush flowers and compact growth, growing 4 metres tall.
  • Kings Park Special: A hardy variety with compact growth, highly popular as a hedge or screening plant, featuring profuse, large, bright red flower spikes, reaching 4 metres tall.
  • Harkness: A hybrid between Callistemon citrinus and Callistemon viminalis, featuring fountain-like arching branches, green-grey foliage, and profuse show-stopping scarlet bottlebrush flowers, attaining 5 metres in height.
KC Sheng is the lead author of arid sage. He is an enthusiast for Australian native plants with a keen interest in the varieties that thrive in dry and arid conditions.
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