Sunday, 12 May 2013

Outsmarting the Blackberries

Blackberries Rubus fruticosus agg are an invasive alien plant in Australia, declared a noxious weed that landowners are obliged to attempt to control. The problem is it escapes into the bush and creates dense impenetrable thickets several metres high and many metres in diameter. Growing along creek banks it can restrict access to the water and easily out competes the natural vegetation.

Blackberry thickets also harbour another invasive alien species -- foxes. The foxes set up home under the protection of the thorny blackberry canes and their diet includes ripe blackberries, leading to seeds being excreted to start new colonies.

 Warning sign on Melba Hill in Canberra.

The blackberries are extremely difficult to control. The best method is to adopt an integrated approach, introducing a rust for biological control, followed by careful spraying with a herbicide. Even within a best practice regime, years of monitoring and spot control must be undertaken before you can be sure an area is blackberry free.

4 comments:

Tim said...

When I was in forestry, we controlled brambles...
and "ruddy"dendrons...
using 2,4,5 Trioxone [Warning: Contains Dioxins] in solution in agri diesel...
we used to call it Agent Tangerine....
the diesel was to both stop the herbicide from washing off in the wet and to help it penetrate the leaves...
the liquid got everywhere, despite so called protective clothing...
ghastly stuff!!

Susan said...

Tim: I suspect they are using a similar toxic mix in Australia, although I couldn't smell it. Fortunately, the strains of blackberry in Australia are particularly suseptible to rust, so spraying with herbicide is a follow up treatment if necessary. They are one of the few plants that cause a problem even in their native habitat, because they form impenetrable barriers. Unfortunately in Europe they are mostly immune to rust.

Tim said...

But, they are far from immune to the new blade I got for the strimmer!!! It is a real bramble-mincer!!

Ken Broadhurst said...

The blackberries here don't grow nearly as fast as they do in hot climates like North Carolina's or California's. But the blackberries aren't anywhere near as sweet and juicy either.