The clover should be mowed to no shorter than 8 inches and before it flowers. If it flowers it will regerminate itself but the clover will have a lower protein content if allowed to flower. I mow my clover usually 2 or at the most 3 times a year to keep it from flowering and then every 4th year I will let it flower and pollinate then after the flowers die I mow it to spread the seed reducing the need to replant purchased seed. The other stuff rape, brassicas, etc. can be left alone.