The first step in weed prevention. The most cost-effective means of managing weeds, is preventing the entry of new weeds into your yard. Once a weed has entered, early detection and removal is crucial to reduce its environmental impacts. It is much easier to treat weeds when present in small numbers than when they are well established. Early detection requires an awareness and understanding of the factors that favour the establishment and spread of weeds. Therefore applying appropriate management practices can prevent or reduce the risks. Plants from commercial nurseries, landscaping suppliers and gardening clubs can also be pathways for the introduction and spread of weeds. Another cause of weed spread is inappropriate use and disposal of garden waste