Acacia Species, Black Wattle

Acacia mearnsii

Family: Fabaceae (fab-AY-see-ee) (Info)
Genus: Acacia (a-KAY-see-uh) (Info)
Species: mearnsii (MEARN-zee-eye) (Info)



Water Requirements:

Unknown - Tell us

Sun Exposure:

Full Sun

Sun to Partial Shade



Foliage Color:

Unknown - Tell us


20-30 ft. (6-9 m)

30-40 ft. (9-12 m)

over 40 ft. (12 m)


15-20 ft. (4.7-6 m)

20-30 ft. (6-9 m)


USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Where to Grow:

Unknown - Tell us


Plant has spines or sharp edges; use extreme caution when handling

Pollen may cause allergic reaction

Bloom Color:

Pale Yellow

Bloom Characteristics:

Flowers are fragrant

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Spring

Late Spring/Early Summer

Other details:

May be a noxious weed or invasive

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

From semi-hardwood cuttings

From seed; direct sow after last frost

Scarify seed before sowing

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant is said to grow outdoors in the following regions:


Gardeners' Notes:


On Feb 23, 2016, coriaceous from ROSLINDALE, MA wrote:

The World Conservation Union has included this species in their list of 100 of the world's worst invasive species, one of only 32 terrestrial species so singled out. [[email protected]]

It is native to Australia and Tasmania, but has now naturalized in North America, South America, Asia, Europe, Africa, many islands of the Indian and Pacific Oceans, and New Zealand. It is widely seen as threatening native habitat and reducing biodiversity.

Hawaii has declared it a noxious weed and prohibited its sale and planting.


On Nov 21, 2010, peejay12 from Porthleven, Helston, Cornwall,
United Kingdom (Zone 9b) wrote:

I bought this plant originally under the name of A. filicifolia, but I think it is A. mearnsii - partly because of its hardiness compared to A. dealbata.

In Southampton, UK(Z9a) it survived -8c in a fairly exposed position while nearby A. dealbata died to ground level.
In Cornwall, (Z9b) I am now growing what I believe is the same species, and again it is growing well and survived a freak frost for Cornwall of -8C. It also retained most of its leaves.
Its hardiness would depend on where the seed was obtained as it is widely distributed along the south of New South Wales. But some plants grow in the Australian Capital Territory - parts of which can be very wet and cold during the winter.

I prefer it to A. dealbata because of its neater shape, and... read more


On Mar 7, 2008, htop from San Antonio, TX (Zone 8b) wrote:

I ahve not grown this plant. Black Wattle (Acacia mearnsii) has become naturalized in Hawaii and California.


On Dec 11, 2004, tonyf from Sydney,
Australia wrote:

In Australia it is subject to borers and has a short life span of 5 to 7 years.