Weeds are opportunistic plants that take advantage of bare soil, moisture and nutrients to grow. Weeds can be a problem in vineyards when they compete with vines for soil moisture and nutrients, interrupt vineyard machinery and operations, harbour vine pests or disease, pose a fire risk or cause taints in wines.

More than 600 weeds have been collated by HerbiGuide – a company that provides information on weeds, pests and diseases in Australian crops, pastures and horticulture (http://www.herbiguide.com.au). Of these 600 weeds, the ones of significance to viticulture as identified by the AWRI, in interviews with over 20 growers across Australia, are listed below.