Flower spikes bristling with stamens make this shrub instantly recognizable: callistemon (Callistemon citrinus) is an evergreen shrub grown for its spectacular summer blooming. Its common name, bottlebrush, comes from the unusual shape of its flowers, while its narrow leaves release a pleasant lemon scent when crushed. Give it full sun and well-drained soil that never stays soggy in winter, and it will flower generously.
| Name | Callistemon citrinus |
|---|---|
| Family | Myrtaceae |
| Type | Evergreen shrub |
| Height | 3 to 10 feet (1 to 3 m) |
| Exposure | Full sun; tolerates partial shade |
| Soil | Well-drained, moderately fertile soil |
| Foliage | Evergreen |
| Blooming | Summer |
Care, from planting to pruning and watering, involves just a few simple steps that will help your callistemon grow lush and flower abundantly.
Growing callistemon in the ground is best suited to areas with relatively mild winters.
It’s recommended to plant callistemon after the last frost spells, preferably in spring.
In colder regions, favor growing callistemon in pots so you can move the plant under cover when freezing weather arrives.
Callistemon is easily propagated through cuttings.
You can balance the shrub’s growth in spring, but avoid pruning too severely.
To maintain a compact appearance, prune the year’s new shoots back by up to half their length after flowering.
In summer, you can remove developing seed capsules if you want the plant to put more energy into new growth and flowering. Wilted flower spikes can also be removed to keep the shrub looking tidy.
Newly planted callistemon needs regular watering at first to encourage root growth and help the plant settle in.
Once properly established in the ground, callistemon can tolerate periods of drought. Water during prolonged dry spells, especially in summer, to support healthy growth and flowering.
Potted callistemon needs more regular watering. Water when the surface of the potting mix has started to dry, while making sure excess water can drain away freely.
Callistemon is generally a robust shrub. Various garden pests and diseases may occasionally affect it, but they rarely pose a serious threat when the plant is growing in suitable conditions.
The few jobs a callistemon requires are each tied to a particular time of year. Here’s what to do, and when, at a glance.
| Season | What to do | Why it matters |
|---|---|---|
| Spring | Plant out once the last frosts have passed | Protects young plants from late cold spells |
| After blooming | Cut the year’s new shoots back by up to half | Keeps the shrub compact and well shaped |
| Summer | Remove spent flower spikes and, if desired, developing seed capsules | Keeps the shrub tidy and encourages new growth |
| Summer | Water during prolonged dry spells; water potted plants more regularly | Supports healthy growth and flowering |
| Winter | Move potted specimens under cover in colder regions | Protects the plant from severe frost |
Follow this simple rhythm and the shrub will keep its attractive shape and flower freely each summer.
Garden centers offer far more than the plain species, from compact bottlebrushes suited to pots to larger, arching forms that can develop into small trees. The table below compares some of the bottlebrushes most often grown, so you can match flower color and habit to the spot you have in mind.
| Variety | Flower color | Habit and size | Best use |
|---|---|---|---|
| ‘Splendens’ | Crimson scarlet | Bushy, arching, medium | Sunny border or warm wall |
| ‘White Anzac’ | White | Low and spreading | Ground cover, banks |
| ‘Perth Pink’ | Deep pink | Upright, bushy, medium | Mixed shrub planting |
| ‘Kings Park Special’ | Red | Vigorous, upright, tall | Screening or specimen shrub |
| ‘Little John’ | Deep red | Dense, compact mound | Pots, low borders |
| ‘Endeavour’ | Bright red | Upright, bushy, medium | Hedges or shrub borders |
| ‘Violaceus’ | Purple-red | Bushy, medium | Unusual flower color in borders |
This evergreen shrub is particularly striking when covered with its abundant and unusual flowers. Its common name, bottlebrush, comes from the cylindrical flower spikes, whose numerous protruding stamens make them look remarkably like the brushes traditionally used to clean bottles.
Native to eastern and south-eastern Australia, callistemon thrives in relatively warm climates when planted directly in the garden. In colder regions, it adapts well to growing in pots or containers that can be moved to a sheltered, frost-free location in winter.
You can encourage more abundant flowering with an appropriate fertilizer during the growing season, particularly for plants grown in containers, where nutrients are gradually depleted.
The name Callistemon comes from Greek words referring to the plant’s beautiful stamens. The specific name citrinus refers to the distinctive lemon scent released by the leaves when they are crushed or rubbed.
For a callistemon planted in the ground, concentrate watering on the establishment period and prolonged summer droughts. Plants grown in pots need more regular watering, but always allow excess water to drain away: callistemon dislikes permanently waterlogged roots.
