Question
My yard is mostly composed of nice bluegrass, but mixed in with it is a lot of tall fescue and zoysia.  The tall fescue looks terrible all of the time, and, because I live in Ohio, the zoysia is brown for most of the year.  Is there anything I can do to get rid of these other types of unwanted grass in my yard without replanting the whole thing?  I have already spent countless hours pulling it out by the roots, but it always comes back.  I don't know what to do.  

Answer
Unfortunately they all have similar growing conditions which will make selective eradication impossible.

The best suggestion I can give is to mow the lawn low (2.0-2.5") with each mowing and fertilize in early and late fall as opposed to spring.

This should keep the KBG happy and the tall fescue and zoysia off balance, but I doubt it will control the other grass types significantly to the point where it will eliminate them.

sorry.