The bottle brush plant, or Callistemon, is a type of flowering shrub. Native to Australia, the shrub is now grown throughout Canada and the United States as both an indoor or outdoor plant. The shrub is popular for ornamental purposes thanks to its red brush-like flowers. Implement a proper care schedule to ensure a healthy bottle brush plant and a large production of eye-catching flowers.
Water the bottle brush plant twice daily, or as often as needed to keep the soil around its base damp. Add mulch, such as compost or dried grass, around the plant to conserve moisture. Though the bottle brush can grow in dry conditions, bottle brush plants thrive best in moist environments.
Fertilise the bottle brush plant twice a year. Administer a standard low-phosphorous garden fertiliser once at the start of spring and once in the fall. This coincides with the start and end of the bottle brush plant's growing season. Liquid or granulated fertiliser can be used and is widely available at most garden stores and nurseries.
Prune the bottle brush to encourage new branch growth and healthy flower production. Use pruning shears to trim the tip of a bottle brush branch right behind its cluster of flowers after the flowers have wilted. Pruning can be done throughout the year but should be stopped in the fall in cold climates, where frost may burn and kill young growth.
Collect the bottle brush plant's seeds if you wish to grow new plants. Allow several flowers to wilt and develop into fruit. Pluck the fruit off the plant when it is soft. Place in a paper bag and store until the fruit pops open to release the plant's seeds. Plant the seeds a half-inch in the ground or in a pot and water daily to encourage germination.
Monitor the bottle brush plant for pests. The hardy plant may sometimes experience an infestation of mites or similar insect pests. Mist the plant with a standard insecticide spray intended for garden use. Example products include those formulated with sulphur or horticultural oils such as neem oil.
If growing the plant in a pot, place it in full sun to encourage healthy foliage.