I have a very thin bermuda lawn that is full of weeds. I am trying to combat the weeds, but want/need to seed fescue in the shady areas because bermuda will not grow in the shade. How am I supposed to go about this? I need to put the seed down now, but I also need to spray for weeds now and apply a pre-emergent plus fertilizer to the lawn soon. Should I just be very careful to not allow any of the fertlizer/weed killer to contact the seeds? Please help!