Question
What kind of grass is Marathon II (tall fescue, fine fescue, bermuda, or other? and what type of ready to use weed killer I can use on it?

Thanks
Frank

Answer
Marathon II is a type of tall fescue; and I am not ducking your other question when I say "a wedkiller that is labelled for it". I do not know what tall fescue even looks like but if I had to control weeds on any lawn, I would first identify the lawn grass right down to the variety. Next I would identify the major weed problem as to whether it is a true grass or a broad leaf. Only then would I look for a suitable product that will say that it is safe on my lawn grass and that it will kill or slow down the problem weed.