If you have ever cleaned a baby’s bottle you will understand how aptly the bottlebrush (Callistemon) plant was named. With elongated, red, bristly flowers, the bottlebrush is a low-maintenance plant that loves hot weather. A native of Australia, bottlebrush, which can grow to a height of 15 feet, can be grown as a shrub or a tree in USDA zones 8a to 11. Trim your bottlebrush in the winter.
Cut off old flowers and seed pods. Make the cut immediately behind them, according to the Australian National Botanic Gardens.
Prune away any wood that appears damaged.
Take off all bottom branches that are growing closest to the trunk on the interior of the plant. Depending upon the size of the bottlebrush, you may have to go under the plant to get to this growth.
Prune the bottlebrush into the desired shape, if growing it as a hedge.
Remove the top one-third of overgrown bottlebrush plants. This will prompt the plant to grow bushier and produce more flowers next growing season.