How to Grow Acacia melanoxylon Plants in your Garden

Acacia melanoxylon is more commonly known as Australian blackwood. Other names include Blackwood, Blackwood acacia, and Tasmanian lightwood.

This tree is native to Australia, where it mostly grows along the southern and eastern coast. It has become natutralised to Africa, Brazil, and New Zealand.

It usually grows to a height of about 65 feet (20 m), but its size and shape can be pretty variable.

Australian blackwood

Acacia melanoxylon (Australian blackwood), Leaves and flowers at MISC HQ Piiholo, Maui, Hawaii. photograph by Forest and Kim Starr, under creative commons licence.

The bark can be dark grey to black in appearance. Acacia melanoxylon has phyllodes as opposed to leaves for foliage.

The phyllodes are greyish green and range from 1.5 to 6 inches (4 to 15 cm) in length.

Acacia melanoxylon

Flowering Acacia melanoxylon Shrub by Forest and Kim Starr, CC.

In its native environment, Acacia melanoxylon has small blooms from July to December.

Gardener's HQ Guide to Growing Australian Blackwood

The growing of Acacia melanoxylon requires a lot of space due to its large size.

A large specimen can grow up to 80 feet (25 m) tall and have a sprawl as wide as 40 feet (12 m).

Because of the size of this tree, it should not be planted near sidewalks, pavement, or underground plumbing.

Full sun is required. This plant is not frost resistant so this tropical plant should only be grown in the warmer USDA zones, nine through eleven.

Australian blackwood Photograph

Australian blackwood Seed Pods by Forest and Kim Starr, CC.

Well-drained soil with medium moisture tends to give the best results.

In proper conditions, the tree will grow quickly so be sure that it is directly planted somewhere that can accommodate a large tree instead of transplanting it at a later date.

Acacia melanoxylon is typically disease-free but may attract pesty weevils. It can help to attract avian pollinators to the area.

Acacia melanoxylon Growing and Care Guide

  • Scientific Name: Acacia melanoxylon
  • Common Names: Australian blackwood, Black Wattle, Hickory.
  • Growing Zone: USDA Zones: 9 to 11. Will grow in mild and coastal areas of Europe.
  • Life Cycle / Plant Type: Evergreen. Shrub or Tree

Plant Details

  • Plant Height (Inches): can easily reach from 16 to 65 feet (5 to 20 m) or higher.
  • Plant Spread (Inches): 12 to 40 feet (4 to 13 m).
  • Time of Bloom: Spring.
  • Flower Details: Fluffy. Racemes (2 to 4 inches (5 to 10 cm). Pale cream to brown, Yellow, or White. Fragrant.
  • Leaf Foliage: Narrow lanceloate, Green.
  • Fruit: Elongated. Flattened pod. Hairless. 1.25 to 6 inches (4 to 15 cm) in length.
  • Bark: Dark Grey to black, scaly. Sapwood: White, Grey or Straw colured.
  • Growth Form: Spreading or horizontal, pyramidal or rounded.

Ideal Growing Conditions

  • Best Light Conditions: Full sunlight, seedling will not grow in the shade.
  • Rate of Growth: Quick.
  • Suitable Soil Types: Deep. Rich and Fertile for best results. Clay, Loamy, Sandy. Acidic, Neutral, or slightly alkaline pH. Well drained
  • Soil Moisture: Dry to Moist (Medium Moisture is likely gives best results).

Caring Conditions

  • Care:
  • Level of Maintenance: Low.
  • Propagation: Seed, requires fire. May spread from root suckers (same plant though).
  • How to Prune: Minimal pruning required to help maintain shape.
  • Pests: Weevil, termite, powder-post beetle.
  • Diseases: Generally tolerant of disese.

Further Information

  • Miscellaneous: Entices birdlife to the garden, Non-native to North America. Attractive flowers / blooms. Wood has commercial value and is often used for Guitar making, tool handles, fence posts, and for light constructuion.
  • Genus Detail: Acacia
  • Further Reading and References: Here and Here

Australian blackwood leaves and seedpods

Australian blackwood photograph close up of leaves and seedpods by Forest and Kim Starr; CC.

I hope that you enjoyed this guide on how to grow Acacia melanoxylon. You may also enjoy the following Fabaceae family growing guides: How to grow peas in your garden and Japanese Wisteria .