I have a rye grass lawn that is inundated with a grass weed that I'm told is Yorkshire Fog. Is there a selective weed spray that will target the Yorkshire Fog and leave the rye grass intact? It is too widespread and dispersed in the lawn for a spot weeding.

• It is not possible to use a selective herbicide to control Yorkshire Fog, it is actually a grass. 
• Spot spraying with a systemic non selective weedkiller is the most effective control.
• Keeping the lawn mowed and don't let the grass go to seed will reduce the spread of it.
• The patches that have been sprayed will need to be resown with a lawn seed that matches the exiting grass.
• Spraying off the whole lawn and starting again is the only way to eradicate it.