Dead turf is a term used to describe grass that has died due to lack of water or other environmental factors. It is also known as brown patch, which is a type of fungal disease that affects grass and other plants. THATCH is a layer of dead organic material that accumulates on the surface of the soil and can prevent water and nutrients from reaching the roots of the grass. THATCH can be caused by over-fertilizing, mowing too low, or leaving grass clippings on the lawn. Removing THATCH can help revive dead turf and restore it to its former lushness.