Bottlebrush (Callistemon) is a member of the family Myrtaceae. This evergreen is an Australian native that is hardy in USDA planting zones 8, 9, 10 and 11. There are varieties of cultivars, and their bottlebrush-like flowers bloom spring through summer. Though red is the most common color, various cultivars also bloom in purple, pink, white, green and yellow. Bottlebrush is a good addition to butterfly gardens, as they attract butterflies and hummingbirds. Plants are relatively hardy and even novice gardeners should have success growing them.
Select a planting site situated in full sun for most of the day.
Remove weeds, grasses or unwanted vegetation from the planting site, as they will compete with the plant for water and nutrients.
Plant the bottlebrush in medium-rich soil that drains well. Amend the planting site with compost or peat, working it into the existing soil to a depth of approximately 1 foot. Add sand to the existing soil and create a raised bed of approximately 1 to 2 feet high if the planting site drains poorly. Pile the soil up and pat down firmly when creating a raised bed.
Plant the bottlebrush at the same depth it was growing inside its container. Make two to three vertical slashes through the root ball, if the plant’s roots are root bound. Dig a hole two times wider than the bottlebrush's root ball. Place the plant in the hole. Cover with soil and tamp down with your foot to release any remaining air pockets.
Water the bottlebrush three times per week during periods of hot weather, depending on your local weather conditions. Allow the sprinkler or hose to water the plant for approximately 10 minutes to fully saturate the roots. Cut back the watering to once every two weeks during winter months.
Place 2 to 3 inches of mulch around the base of the bottlebrush to help the soil retain moisture and cut down on unwanted weed growth. Apply a fresh application of mulch annually.
Fertilize the bottlebrush monthly with a balanced liquid fertilizer, following the instructions on the package. Spray the entire plant’s foliage with the liquid fertilizer until the leaves are soaked. Apply 2 to 3 inches of compost or manure around the base of the plant annually and water in well after the application.
Treat pest-bothered bottlebush plants with insecticides designed specifically for the insects being targeted. Spider mites, thornbugs, various scale insects and canker can affect bottlebrush plants.
Protect bottlebrush plants from frosts or freezes by wrapping the entire plant in holiday lights, or placing a blanket or sheet over the entire plant. Saturate the roots before a frost and soak the foliage to help the plant retain heat. Allow the sprinkler or hose to run on the plant for approximately 10 minutes.