Clover is a common weed that plagues lawns in the United States. It is in the legume family and, depending on the species, is either an annual or perennial. The most common types of clover are black medic (an annual clover with small yellow flowers) and white clover (a perennial clover with white flower heads). When trying to eliminate a clover infestation in your lawn, you need to ensure that you kill the clover and not your grass. This is more of a concern on Southern lawns, where certain herbicides can harm or possibly kill the lawn.
Prevent new clover invasion into your yard by applying 0.454kg. of nitrogen per 1,000 square feet. Read the fertiliser bag to determine how to set your fertiliser spreader to apply this rate. Clover thrives in lawns with low fertility, so upping the nitrogen allows more vigorous growth of grass.
Pull out established clover plants by hand if they are few and far between in your yard. Pull them out before they flower and go to seed to prevent germination of new plants.
Apply herbicide to your lawn. For warm-season grasses, use an herbicide that contains mecoprop and dicamba. For cool-season grasses, use an herbicide that contains triclopyr. Apply the herbicide to your entire lawn at the rate indicated on the packaging. Allow a few weeks after application for it to work, and reapply it to areas where clover was not killed by the first application.
Practice good watering habits. Clover is very drought tolerant -- much more so than grass. Irrigate your lawn with an inch of water per week if rainfall totalling that amount does not occur. Keeping a healthy stand of grass prevents clover seed from germinating and taking root.
While cool-season grasses will tolerate all types of herbicides that control and kill clover, warm-season grass will be injured by herbicides containing triclopyr. Always read the label of the herbicide to determine if it is safe for use on your grass.