Eight grasses were oversown on steep north and south aspects at Hunua, North Canterbury, either initially with clovers or three years after oversowing clovers. On the north aspect, cocksfoot established and persisted best but ryegrasses were superior on the south aspect. Here the later sowing was much superior, as by then the original dense cover had disappeared, but on the north aspect time of grass introduction made little difference. Clover introduction resulted in a threefold increase in dry matter production on the south aspect, which produced double that of the north aspect. Ryegrasses raised yields still further, but depressed resident grass production.