Bottlebrush (Callistemon citrinus) can grow up to a height of 12 feet and a width of 15 feet. This native Australian ornamental shrub gets its common name from the red flowers it produces, which look like bottle brushes. Bottlebrush plants can form dense thickets when suckers are not controlled. The suckers also use nutrients required for healthy new growth. An excess of older, interior branches can interfere with new growth and flowering. Prune bottlebrush plants during late winter or early spring to encourage healthy new growth and flower production.
Cut the lowest branches on the bottlebrush plants first. Cut the branches close to the trunk.
Cut suckers from the base of the trunk--if they are above soil level--or cut them down to ground level.
Cut dead, diseased, weak or damaged branches from the Callistemon shrub.
Cut off any branches that cross over other branches on the inside of the bottlebrush plant. Do not remove more than 1/3 of the branches during the first 3 years of the Callistemon's life. This can cause it to go into shock.
Cut the ends of the branches to shape the canopy. Bottlebrush plants look best when they are shaped like an open umbrella. Cut the stems immediately behind faded, dead or wilting flowers.