EXTERNAL TEXT SOURCE:

AUSTRALIAN NATIONAL BOTANIC GARDENS

http://osprey.erin.gov.au/anbg/index.html

Wattles

Wattles are members of the genus Acacia and belong to the family Mimosaceae. There are about 750 species of Acacia found throughout Australia. Australia's national floral emblem is Golden Wattle, Acacia pycnantha. Wattle Day is celebrated on 1 September.

Where do they Occur?

Their habitat ranges from coastal to sub-alpine regions and from high rainfall to arid inland areas. Acacias also occur in Africa, South America and throughout other warm areas of the world.

Flowers and Foliage

Wattles show a range of foliage and flower types. The true leaves are divided into leaflets (bipinnate), but a large group of wattles develop modified leaf-like structures (called phyllodes) soon after germination. A few species lack true leaves or phyllodes; in these plants modified stems (called cladodes) function as the leaves. The foliage colour of wattles ranges from light or dark green to blue or silver-grey.

Flowering times of wattles vary greatly, with the bulk of species flowering in spring and summer. Other species flower during autumn and winter and, with careful selection, it is possible to have flowering wattles in the garden at all times of the year. The flower heads are either spherical or cylindrical and vary in colour through cream, pale yellow to gold. One species (Acacia purpureapetala) has purple flower heads. The flower heads of many species are delicately perfumed.

Wattles as Garden Plants

Wattles make excellent garden plants. They range from prostrate and low-growing species to larger shrubs and shade trees. Most respond to pruning immediately after flowering and, if carried out regularly, pruning can extend the life of the plant.

The main pests are stem borers which can be controlled by probing with flexible wire or by injecting a few ml of alcohol into the holes. Galls are often more difficult to control, but removing the effected branches can reduce the problem. Acacia bug (Eucerocoris tumidiceps) can cause damage to the foliage of wattles with phyllodes and is difficult to control. Treatment with a systemic insecticide may be required.

Wattles are a good source of pollen, some species are popular with bee-keepers. The seeds are also an important source of food for birds. Some wattle seeds also provided a food source for the Aborigines. Mostly they were ground into a flour and cooked like damper.

Propagation

Propagation from seed is the most common method. Seeds are readily available and can be stored for many years. The very hard seed coat needs to be softened before germination can take place. Pouring boiling water over the seeds and leaving them to soak for 24 hours will usually do this. The infertile seeds will float to the surface and should be discarded. Swollen seeds can be sown, the others can be re-treated.

Many species of Acacia can be grown from cuttings using firm new seasons growth. Cuttings from species with phyllodes are easier to strike than those with bipinnate leaves.

Commonly Grown Wattles

The following wattles will grow well in most temperate parts of Australia and most have been successfully cultivated at the Gardens.

Snowy River Wattle Acacia boormanii: The bright yellow flower heads of this shrub open in late winter and spring. Plants grow best in well-drained soils in full sun or part shade and can tolerate extended wet periods. Snowy River Wattle grows to about 3 m and has narrow grey-green foliage. The shrubs do sucker but they are not highly invasive.
Blackwood Acacia melanoxylon: Blackwood is a useful large shrub or tree which can grow to 30 m (usually much smaller in cultivation). The pale yellow flowers open in spring, but are not very obvious. Blackwood grows well in many situations and is frost tolerant. The trees are a source of beautiful timber.
Ovens Wattle Acacia pravissima: This widely cultivated wattle grows well in full sun or part shade and has attractive triangular-shaped foliage on pendulous branches. The bright yellow flower heads open in spring and add a sweet perfume to the garden. Shrubs grow to about 6 m. A prostrate cultivar, A. pravissima 'Golden Carpet', is also available.
River Wattle Acacia cognata: The delicate narrow foliage and pendulous branches of this tall shrub make the River Wattle an elegant addition to any garden. The pale yellow flower heads open in spring. Plants grow well in light to heavy well-drained soils in areas of dappled shade or part sun. Plants grow to about 5 m.
Mount Morgan Wattle Acacia podalyriifolia: The bright yellow flower heads of the Mount Morgan Wattle brighten the garden over winter and early spring. The foliage of the shrub is an attractive silver-grey. Plants grow quickly in moist well-drained soils throughout temperate and tropical Australia. Mount Morgan Wattle grows to about 8 m.
Fringed Wattle Acacia fimbriata: This small tree grows to 7 m and produces masses of golden yellow flowers in spring. It grows in a variety of situations in either full sun or part shade, on well-drained soils. Fringed Wattle is an ideal plant to give protection to ferns and other shade-loving plants.
West Wyalong Wattle Acacia cardiophylla: West Wyalong Wattle is a rounded shrub which grows to about 3 m. The greyish feathery leaves give the plant a delicate appearance. Masses of golden yellow flower heads open in spring. Plants grow best in well-drained soils in a sunny position. West Wyalong Wattle is drought and frost resistant.
Golden Wattle Acacia pycnantha: The Golden Wattle is famous as the floral emblem of Australia. Plants may grow to 10 m and produce masses of golden yellow flower heads from winter to spring. The foliage is deep green. Plants grow quickly in well-drained soils in full sun or dappled shade.
Hairy Wattle Acacia vestita: This beautiful shrub grows to about 3 m and bears triangular-shaped grey-green foliage on pendulous branches. The golden yellow flower heads open in spring. Plants grow well in most soils in full sun or partial shade. Hairy wattle is a useful screen plant.