Question
What type of seeds should I use for overseeding in fall, so that in spring the grass sprouts. I think, this way I can control crabgrass. I can also use crabgrass preventer which do not go together with overseeding in spring.

Answer
I'd recommend Kentucky Bluegrass in sunnier spots and fine fescues (Creeping or Chewings) in the shadier areas. Definitely wait until the new seedlings have been mowed once or twice before applying the crabgrass preventer though.

Good luck!

-Chris Brown
www.TheLawnCoach.com