This paper reviews the problem of introducing grasses into tussock grassland. The remarks will be of value to those who are contemplating oversowing grasses into tussock grassland. Where an extended grazing season, improved pasture quality or increased total yield of tussock grassland is required, cocksfoot and ryegrass is recommended to provide higher spring and autumn yields. However, this intended advantage is often reduced by poor establishment and/or survival (often less than 1%) particularly if attention is not paid to correct establishment techniques. The contribution of the oversown and resident grasses to total yields will vary, largely due to management practices. In addition on sites where adventive grasses like browntop are already present, there is little evidence to suggest that oversowing grasses will improve total yields or seasonal pasture productivity. This review illustrates that the introduction of grasses into tussock grasslands may not always give the benefits sought. Keywords: Oversowing, establishment, survival
