Home & Garden Columns
Bottlebrush trees are one of the bright, amusing notes on our streets, sporting those funny flowers shaped like, yes, bottlebrushes with perky little green-leaf tufts at their ends. They’re tough and not pest-prone, and easy enough to find in nurseries. Their hard little leaves and shreddy bark give them a ragamuffin air to match the spiky inflorescences. The red flowers attract birds—hummingbirds of course, but I’ve seen a stray Cape May warbler, a nectar-seeker in winter, using them too.
We’ve lost a few of the trees that I knew in North Berkeley, but enough of them are in gardens and public places than I don’t worry about a population decline. Besides, they’re exotics—from Australia—and as far as I know in no danger in their home range.
The bottlebrush—Callistemon—species I see here, mostly of the weeping (C. viminalis) or lemon (C. citrinus, formerly C. lanceolatus) sort, are among those trees that people ought to be planting under utility wires, because they generally don’t get very tall and it’s easy to control their height. They’re fun to prune.
In fact, my general complaint about local weeping bottlebrushes is that people don’t know how to prune them. Longtime readers of this column will not be surprised to hear that, as people who prune despite not knowing how are a frequent target of my uncharitable scorn. But weeping bottlebrush trees, especially, practically have roadmaps built in.
It’s easier to show you than to tell you, as Bre’r Rabbit would say, but here’s a first step: Don’t just shear them at the bottom in the equivalent of a bowl cut. Get underneath—after nesting season is over, please—and start cutting the branches closest to the trunk. They almost have “Cut Here” dotted lines; just cut on a leaf node, above a row of seedpods if there are any on the branch. For the first few, though, cut next to the trunk.
When you’ve opened those up a bit, stand and watch the tree. It should be a bit more flowing when it moves now, a bit bouncy but graceful. Cut a little more, still from the inside. Leave some deeper layers, but make them of uneven lengths.
When you have two forks in a twig, cut off the lower, inside one. This is counterintuitive only the first time, and is a good strategy with any weeping tree. Weepers should reach out a little, bounce like a waterfall; half their charm is in their motion in the breeze and their illusion of flowing even when still.
If you end up with something that looks like a parasol, stop. The tree will soon fill in some of the space, and you’ll be able to form your own ideas of what you and the tree can make happen next. Within whatever limits you have—traffic, the side of a building—try to broaden the reach of the tree, to let it move and dance and show off its flexibility.
There are two reasons for the opening-it-up strategy: Those inside branchlets are the ones that accumulate dirt, insects, mold, and such, and because they get less sun they’re less vigorous. Callistemons are tough, but there’s no need to stress the tree by making part of it a bug-and-pathogen farm. Also, they really aren’t supposed to look like bottlebrushes themselves: the common name refers to their startling, usually red, flowers.
Since the ones we see here are generally strictly ornamentals and generally small, it’s startling to read a quote from nineteenth-century handbook of Australian plants that recommends the wood of lemon bottlebrush for “ship-building and wheel-wright’s work and… mallets.”
But if you’ve ever had to cut one down, you’ve come to appreciate the toughness of the wood. The wood of some Callistemons is recommended for use in fenceposts and such things that come in contact with soil, because they resist rot. But mostly they’re ornamentals here. They’re tough enough to be used in hot places like parking lots, and their density is easily controlled so they make good screens of whatever opacity you like. I haven’t heard that they’re invasive, but if you live next to wildlands, check that out before planting one. Plant it high and don’t let it stand in water, and it’ll be good company.
Photograph by Ron Sullivan:
The exuberant flowers of weeping bottlebrush attract birds as varied as hummingbirds and Cape May warblers. This one is a street tree on Park Avenue in Oakland.