SALISBURY — Most fescue lawns in Rowan County have ample strands of crabgrass and other weeds. Abundant rainfall and hot temperatures favor weed growth of endogenous weeds and drastically reduces growth of cool season fescue. In many instances the entire lawn is mostly weeds.
If this scenario best describes your lawn, it would be most practical to kill the entire lawn and start over. 

Read the full article on how to kill your lawn on Farm Carolina. All about Garden, Food and Farm!