Kikuyu grass was originally brought to California and other warm-weather locations for erosion control, but it has since spread to the point that the state of California as well as the federal government both now consider kikuyu an invasive weed. Even small pieces of the grass, spread by lawn mowing equipment, are enough to establish the grass in areas where it is unwanted. Because this is such a fast-growing grass (as much as 1 inch per day) and it can be spread through seeds, roots or above-ground stems, by the time the weed is discovered the only way to eradicate it is through the use of a non-selective weed killer, preferably one containing glyphosate.
Set your lawn mower to 1/2 inch and scalp your kikuyu lawn. Use a thatch rake to rake up all cuttings and as much thatch as possible. Bag and dispose of all cuttings. Clean your lawn mower thoroughly after mowing. Remove all pieces of kikuyu grass, no matter how small.
Water your lawn thoroughly for seven days. Allow your sprinklers to run for at least one hour the first day in order to ensure that all seeds and roots are wet and encouraged to grow and keep the ground damp for the next week.
Stop watering on the seventh day and on the eighth day spray the yard with a non-selective herbicide that contains glyphosate. Follow all manufacturer instructions when spraying glyphosate and wear gloves, eye protection and a breathing mask. Don't spray if it is windy and be extremely careful not to spray any glyphosate on plants you wish to keep, as this herbicide kills anything it touches. Don't spray glyphosate if rain is forecast over the next 24 hours.
Begin watering the lawn again 24 hours after spraying with glyphosate. Keep the ground damp but not soggy for the next seven days.
Spray glyphosate a second time seven days after the first spraying in order to kill any new growth that has sprouted since the last spraying.
Wait another seven days for all weeds to die and then rake all dead vegetation with a thatching rake, bag it and dispose of it.
Rototill the area and rake out any remaining roots and other debris. Level the area with your rake and prepare to plant a new lawn.