Bottlebrush (Callistemon species)

Few gardeners can resist the flamboyant spring and summer blooms of native bottlebrush. Red and pink shades dominate flower colour choices, but mauve, white and even green-flowered species and cultivated varieties are available. Bees and nectar-feeding birds flock to blooms. Birds also snack on the small, seed-filled woody cones and pick off insects that hide within bark crevices.

Bottlebrush thrive in most garden situations, even if your soil is heavy clay. Best of all, there is a size to suit every situation:

  • Pots and small gardens Little John, Captain Cook, Matthew Flinders.
  • Medium shrubs and informal hedges Rose Opal, Pink Alma, Purple Splendour, Saint Mary MacKillop.
  • Tall shrubs and trees King’s Park Special, Dawson River, Hannah Ray, Wild River.

Growing conditions

Aspect North, north-east or west facing positions that provide potentially the most available sunlight are preferred, but bottlebrush also tolerate shade for some part of the day. Established plants buffer strong winds and are ideal for creating shelter and privacy screening. On steeper sites, plant bottlebrush at the base of slopes where soil moisture naturally accumulates.

Soil Bottlebrush are perfectly happy in clay soil that grevilleas and some other native plants will not tolerate. They cope with everything from poor soil fertility through to deep, rich loam as well as a wide pH range. Improve the soil prior to planting by cultivating and adding home-made compost or Seasol Super Compost. Improving the soil’s water-holding ability is the key to success in light or well-drained soil.

Climate Bottlebrush occur naturally all over Australia, but the greatest diversity occurs along the east coast. They cope with both cold and extreme heat, tolerating everything from medium frost in southern and inland regions through to flooding rain and temporary waterlogging in the tropics. You will find the greatest choice of varieties in nurseries during late spring and early summer.

General Care

Watering Bottlebrush enjoy regular watering, particularly when plants are young. Taller, well-established shrubs have deeper roots that are often able to access subsurface moisture. Seasol and Seasol Super Soil Wetter & Conditioner can be applied to the soil at any time, but are particularly beneficial during plant establishment, when it is dry or during other periods of stress.

Feeding and Mulching PowerFeed with Troforte All Purpose including Natives is perfect for bottlebrush. Add to the soil at planting and during spring, summer and autumn until plants are well established. Mature bottlebrush benefit from additional nutrition after flowering and following any pruning, so be sure to fertilise and water well at these times. You can also boost growth at any time of year with liquid PowerFeed All Purpose including Natives. Mulch plants to keep the roots cool and retain soil moisture.

Pruning Tip prune young plants to promote bushy growth. Annual pruning of established plants is not essential, but will improve the shape and control the height and width your bottlebrush achieve. This yearly trim is best done immediately after flowering. Pruning at other times jeopardizes flowering as you will be cutting off the wood on which spring and summer blooms develop. Where possible, avoid severely pruning old established bottlebrush back to bare trunks as weak trees may fail to re-shoot.

Watch out

  • Caterpillars New leaves that appear to be stuck together may be hiding caterpillars of the callistemon tip borer. Control outbreaks by pruning off the affected growth.
  • Sawfly larvae These are more obvious as clusters of ugly, writhing grubs that feed on the foliage.
  • Scale insects Can may be found on stems and the undersides of leaves, particularly following long dry periods. Both of these pests can be controlled with Earthcare Enviro Pest Oil or EarthCare White Oil insect spray.
  • Black sooty mould  A common by-product of scale infestation, but naturally disappears over time as scale is controlled. Bottlebrush are potentially susceptible to myrtle rust. Speak to staff at your local nursery about the most suitable, disease resistant bottlebrush varieties for your region.