Question:
Should I buy Crabgrass + feed or just go for the weed and feed for my lawn (I have no idea if I have crabgrass or not). I live in central Ohio.
Go for the 'weed and feed'.
Crabgrass will only grow where there are bald spots
or where it doesn't have to compete with regular grass.
Learn what crabgrass looks like, as there is still time to apply crabgrass preventer.
Don't spend money needlessly - be frugal (cheap ) !