How do I prune a bottlebrush?
Wait for the flowers to finish
The Australian National Botanic Gardens says bottlebrushes can be lightly pruned after flowering to keep their shape, and prefers cutting just behind the flowers as they finish.
Cut into this season's growth
Light pruning means cutting into the new season's wood, not back into the bare interior where there's little or no foliage.
Skip the cut just before winter
The Gardens makes an exception for late pruning just before winter, because the new growth that follows may be damaged by frost.
Keep your feet on the ground
Secateurs for the flower heads, loppers for anything thicker. If you can't reach it standing on the ground, leave it for someone with the right gear.
How big do bottlebrushes get?
About 40 species are currently called Callistemon, and most come from eastern and south-eastern Australia (some authorities now include them in Melaleuca, though not everyone agrees). Size varies a lot. The crimson bottlebrush (Callistemon citrinus) is usually a medium shrub about 2 m by 2 m, while the Botanic Gardens gives 5 to 7 m for the weeping bottlebrush (Callistemon viminalis) and 5 to 12 m for the willow bottlebrush (Callistemon salignus).
They're street trees as well as garden shrubs: Greater Shepparton's 2017 Urban Forest Strategy names Weeping Bottlebrush among its most common urban trees. We came up empty on bottlebrush roots, so we can't tell you how they behave near pipes or paths.
Weeping forms and tired old shrubs
Go gently with a weeping bottlebrush. The Australian Native Plants Society notes that pruning can destroy the appearance of the weeping forms, so tidy the tips rather than reshaping the tree.
Most other bottlebrushes, the crimson included, can be pruned severely if they need it. For an old, leggy one, the Botanic Gardens has had some success with basal pruning, taking every branch off at ground level and letting it regrow. It doesn't always work, so treat it as a last try before replacing the plant.
When is a bottlebrush an arborist job?
Once it's grown into a tree. A willow bottlebrush heading towards 12 m over a roof or a fence, branches you'd need a ladder for, a split trunk, or a removal with its stump are all arborist work. The tree pruning and stump grinding pages explain those jobs.
Height can bring in council rules. In the City of Parramatta, permission may be needed for any tree or palm 5 metres or taller, whatever the species, and a grown weeping bottlebrush can reach that. Ask your council before removing a big one; our tree removal permits page lists the ones we cover.
If new growth is failing, keep in mind the City of Sydney lists bottlebrush among the myrtle family plants myrtle rust can affect. A tree health check will sort out what's going on.
Bottlebrush: what to do next
A bottlebrush is about the friendliest tree on this list to look after yourself. We'd make a habit of a quick tip prune as the flowers fade each year, and only bring in an arborist once it's taller than you can reach or it's growing over something that matters.
Want an arborist to look at it?
Tell us the job and your postcode, and a local arborist calls you to talk it through.