Flooding, like most natural disasters, can create new opportunities for weed invasion in the flood zone. A key part of our recovery efforts must be to identify and control new weeds early, which will save money and avoid more back-breaking work in years to come.
Floods create damage and disturbance by removing soil and vegetation, inundating or smothering groundcovers and pasture grasses, and by depositing new weeds onto previously clean areas. Bare soil, high soil moisture, and lack of competition from pastures or native plants creates ideal conditions for the germination and rapid growth of weeds.
Weed spread through flood activity
Herbaceous weeds like Parthenium weed, Noogoora burr and thistles can emerge quickly where silt has been deposited, shrubs and woody weeds with larger seeds or floating branches like Tropical soda apple, Cockspur coral tree, Groundsel bush and Prickly pear can establish amongst flood debris, whilst vines like Madeira vine, Morning glory and Cats claw creeper will quickly overtake shrubs and trees in the riparian zone. Aquatic weeds are especially prevalent after floods, using floodwaters as their primary dispersal mechanism to infest new dams, wetlands and waterways. New weeds may also pose toxicity problems for livestock. Animals may graze on emerging weeds or even poisonous native plants if their usual fodder plants are absent.
What can we do?
Acting early to identify and control new weeds is an essential part of flood recovery. Inspect disturbed riparian areas, flood debris and the high-water mark, dams, ditches and waterways on your property. Record what you find and contact Council’s biosecurity officer to help you identify any suspicious or new plants on your land.
The attached videos discuss some approaches that you can take following a flood and demonstrate some of the key weeds to look out for in our region.
As always, the NSW WeedWise app and website provide extensive weed profiles, control measures and biosecurity requirements: NSW WeedWise
