It didn’t take long for the Blackberry introduced from Britain into N.S.W. in the 1800’s to escape into the wild and be recognised as a highly invasive weed.
Blackberry is now widespread, recognised as one of the worst weeds in Australia and listed as a Weed of National Significance (WONS).
The species thrives in a wide range of habitats and poses a threat to agriculture, industry, natural ecosystems (especially riparian areas) and human safety and amenity.
Blackberries are spiny, perennial shrubs with trailing stems and can form dense thickets two metres in height, covering vast areas and dominating the landscape. They provide ideal harbour for feral pigs, cats, rabbits and foxes, all of whom in turn help to spread their seeds.
Blackberries can also spread in water systems and their resident feral animals can impact water quality.
In places they create a huge fire hazard, not only because of their fuel load but because they are impenetrable and exclude access.
A biological control leaf rust fungus has been effective on some species of Blackberry, reducing the plant’s ability to grow and reproduce. However, it has only been successful in areas with temperate climates and high annual rainfall.
Landholders who are reluctant to control Blackberries in order to harvest their berries should look instead to the non-invasive thornless varieties of blackberry, boysenberries, youngberries and raspberries which are readily available and grow very well in the South West.
”Blackberry can tolerate frost, fire, drought and periodic inundation."