Answer: Wire grass is a common name for Bermuda grass; Goosegrass or Silver Crabgrass (Eleusine indica), an annual weed; Johnson grass is a perennial weed, growing upwards of 4' high. It is the most difficult weed to control because it has perennial roots and needs to be spot treated with a vegetation killer such as Round-Up. Round-Up will kill anything it touches, so be careful when using it or you could kill your lawn, as well.
If you have wire grass, goose grass or silver crabgrass, you can use one of the following products. Since you didn't identify the type of grass you are growing, not all of these herbicides may be suitable for your lawn. Be sure to read and follow label directions, as make sure it is safe to use on the type of lawn you're growing:
ProTurf Goosegrass/Crabgrass Control
Turf Weedgrass Control, Halts
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