With clover, you mainly have to manage the competition. For a new plot, I would want to mow the clover itself as little as possible while it is getting established so the individual plants will mature and produce seed as early as possible, but if weeds begin to overtop the clover, you either need to spray with a selective herbicide that will not harm your clover or mow just enough to release the clover from that weed competition...and before the weeds go to seed as was said earlier orthe clover'scompetition will be compounded.