usually i like to wait 2-3 weeks after discing my soil and then spray roundup before planting. if you spray now it will kill the clover that has emerged. wait till the clover reaches 3-4inches and spray with poast plus for grasses. mowing will help with any weeds that come up. another thing that will help next time is planting buckwheat the season before and till it under. it creates a natural herbicide and helps with weeds and grass.