The bottle brush tree is an evergreen that is native to Australia. The name "bottle brush" reflects the characteristics of its bright red flower spikes, which do attract humming birds. This plant can be trained as a shrub or a tree. A mature bottle brush will reach a height of 10 to 15 feet, and a spread of 10 to 15 feet. It is hardy in zones 9 through 11. Reasons for pruning will be to remove dead or broken branches, to maintain a size and shape within your landscape design, to ensure safety along walkways, and to remove any suckers. The bottle brush tree requires only light pruning, which should be done after it has flowered.
Cut away any dead or broken branches immediately, to ensure the health and integrity of the flowering shrub, as broken branches are an entryway for disease. Where you make your cut depends upon the location of the break or the dead branch. You can prune either at the base of the shrub (if it has been trained as a shrub) or at the trunk of the tree, or where the break/dead wood is located. If you are not cutting away the entire branch, then make your cut approximately ¼ inch before a bud.
Use the "tip pruning" technique to maintain the shrub within your landscape design. Flowers are formed on the new growth, so once the tree/shrub has finished flowering, prune just behind the flower by making a lateral cut. You can then deposit the plant material in your compost bin.
Cut off any suckers that are growing from the trunk or from the roots of the tree/shrub. Suckers take away valuable nutrients from the plant.