Lake George, NSW

in flower

dryland trial, Chile

plantation, Kenya

Natural populations

Acacia mearnsii occurs on coastal lowlands and the adjacent tablelands and ranges in south-eastern Australia [1,2,3]. It extends from near Sydney, New South Wales, to the south-eastern corner of South Australia. In Tasmania, in occurs at low and intermediate altitudes. It has become naturalised in parts of New South Wales, South Australia and Western Australia [2]. This species is usually a small to medium-sized tree up to 6–15 m tall, and grows on gentle to moderately hilly topography usually preferring easterly and southerly aspects. Best growth usually occurs on moderately deep forest loams derived from shales and slates [1].

Flowering and seeds

Flowering in this species occurs during December to January [1,2,3]. Pods mature 12-14 months later [1,2]. There are about 20 viable seeds per gram [4]. Nicking or boiling the seeds in water for a minute at 100°C is required to induce germination. The seeds start to germinate in about 5 days if grown at 25°C [4].

Cultivation and uses

Acacia mearnsii is a fast-growing, nitrogen-fixing tree, useful for remediation of degraded sites [2,3]. Provenance variation has been documented in this species [2,5] and there is considerable potential for it to be cultivated well beyond its natural range [7]. It is considered slightly salt tolerant [6]. The wood has industrial potential for paper pulp production, cellulose for rayon and for charcoal and fuelwood production [1]. The bark of A. mearnsii is an important source of vegetable extract used for tanning leather. Industries based in Brazil, China, Kenya, India, South Africa, Tanzania and Zimbabwe grow plantations of A. mearnsii to export tannin to countries such as the UK, Australia and the United States [2]. The tannin produced by the bark has good waterproof adhesive properties for the production of reconstituted-wood and is used in adhesives for exterior grade plywood, particleboard, laminated timber and numerous other industrial applications [2].

Key descriptors:
Climate parameters
Rainfall distribution pattern summer, uniform or winter
Mean annual rainfall: 500-1600 mm
Mean annual temperature: 9-18 °C
Mean max. temperature of the hottest month: 21-30 °C
Mean min. temperature of the coldest month: -2-7 °C
Frosts per year: frost free or more or less frost free, up to 20 or greater than 20
Frost intensity: light to moderate (0 to -5°C) or heavy (greater than -5°C)
Altitude: 2-1070 metres
Tolerance of climate extremes
Drought known to be drought sensitive
Fire: killed by damaging fire does not regenerate foliage
Frost: tolerates frosts in the 0° to -5°C range or greater than -5°C
Soil factors
Texture: clay loam, heavy clay (greater than 50% clay), light to medium clay (35-50% clay), loam, sandy loam, sandy clay loam or sand
Soil pH reaction: acidic (less than 6.5) or neutral (6.5-7.5)
Soil depth: moderate to deep (30-100 cm or greater)
Drainage: well-drained
Salinity: non-saline
Tolerance of adverse soils
Extremes in pH: acidity
Salinity: nil - sensitive to saline soils or slight (2-4 dS m-1)
Soil waterlogging tolerance: nil - sensitive to waterlogged soils
Biological traits under cultivation
Habit: evergreen tree 5-10 m tall or tree 10-20 m tall, usually produces a clear trunk
Longevity: moderate to long lived (>15 years) or short-lived less than 15 years
Growth rate: fast
Coppicing ability: nil or negligible
Root system: shallow and spreading, fixes nitrogen via root symbiot
Erosion control potential: excellent for clayey sites
Wood density: mod. to high (greater than 600 kg/cubic metre)
Carbon sequestration potential: moderate
Potential farm use: good for fence posts or shelterbelt or shade for stock
Specialty products: pollen has value in apiculture, high tannin content in bark
Traditional Aboriginal uses: weapons
Urban use: ideal maintenance free street tree
Wood products: pulpwood (wood chips for paper pulp) or rayon, craftwood (for turnery etc.), flooring (including parquetry), high quality fuelwood, industrial charcoal, light construction, posts (including fencing), speciality timber for quality furniture, wood composites
Potentially undesirable attributes
Fire sensitivity: killed by severe fires (seeder)
Growth habit: shallow roots may outcompete adjacent plants
Weediness: high potential based on its biology


[1] Boland DJ, Brooker MIH, Chippendale GM, Hall N, Hyland BPM, Johnson RD, Kleinig DA, McDonald MW, Turner JD (2006) Forest Trees of Australia. CSIRO Publishing, Collingwood.

[2] Maslin, B.R. and McDonald, M.W. (2004) AcaciaSearch-evaluation of Acacia as a woody crop option for southern Australia. Rural Industries Research Development Corporation Publication No. 03/017, Canberra

[3] Doran JC, Turnbull JW (eds.) (1997) Australian Trees and Shrubs: species for land rehabilitation and farm planting in the tropics. Australian Centre for International Agricultural Research, Canberra [ACIAR books online:]

[4] Gunn BV (2001) Australian Tree Seed Centre Operations Manual. Internal Publication, CSIRO Australian Tree Seed Centre, ACT. [Online at  Accessed March 2008]

[5] Harris S (2007) Victorian Department of Primary Industry Agriculture Notes Black Wattle for Farm Forestry online pdf file: Search site under the Farm Forestry link for the pdf

[6] Jovanovic T, Booth TH (2002) Improved species climatic profiles. A report for the RIRDC/L&W Australia/FWPRDC/ MDBC Joint Venture Agroforestry Program. RIRDC Publication No 02/095, Canberra.

[7] Marcar NE, Crawford DF (2004) Trees for Saline Landscapes. RIRDC Publication Number 03/108, Canberra.

Internet links

ABRS Species Bank:

eFloraSA Electronic Flora of South Australia:

PlantNET National Herbarium of New South Wales:

Victorian Department of Primary Industry:$file/ag0808_nov07.pdf


World Wide Wattle: