Tall Fescue has a wider and coarser leaf blade that typically grows faster between weekly mowings of your lawn. Tall Fescue is a "bunch type" grass meaning it grows in colonies that are close together. When it’s hot out and you don't water your lawn, Tall Fescue begins to thrive. In fact, it will stay green while all your desired grass goes dormant. You do not want this to happen. This will give the advantage towards Tall Fescue and it will begin to thrive and spread rapidly. There is only one way to get rid of tall fescue and that is by killing the area with roundup, digging out the area and replacing it with seed and soil.
However, you can suppress it by raising your blade height to 3.5" giving your bluegrass an advantage and allowing it to grow sideways in order to "choke" the tall fescue out. Also, you should water appropriately (see our watering recommendations page). Tall Fescue likes heat and drought. By watering your lawn appropriately, your bluegrass has a much better chance keeping a stronghold in the lawn and not allowing the unwanted grass to become part of it.
Another grassy weed just like above. The difference is that it is not much of a "bunch grass," instead it just grows and spreads rapidly thru horizontal underground roots called rhizomes. It grows faster between mowings, and flourishes on heat and drought. Use the same methods mentioned above to suppress it, or apply roundup and start over.