Rick Allen and Dirk Spennemann, researchers from the Charles Sturt University, have warned that, if left to their own devices, olives can turn into huge woody weeds that could prove to be a stranglehold on the nation's farmers.

Rick Allen believes that "strategies to prevent the escape [of feral olives] into the surrounding environment should be part of planning for new and existing commercial olive groves," although this is a little easier said then done. Attractive because of the energy source in the oil, many birds and mammals will pick up and carry olives, spreading the seed for many miles.

To date commercial olives cover 5000ha in Australia, with 7000ha more planned, but Allen says, "some governmental regulations may be needed to prevent the spread of olives."