I recently had a sprinkler system put in and everywhere they tore up the yard they threw down seed. The seed that they threw down took every place it landed and is growing like a weed. The new grass grows twice as fast as my established grass, and is a much lighter color. They tell me that they used a Fescue blend,but I don't believe it for a second. It looks nothing like Fescue, the stems are round near the bottom and very thick up top. Does any one have an idea as to what they put down, or any way to kill it with out harming my Fescue turn grass. Thanks for the help I have added pictures to better show the problem.