Choose from natural or chemical methods to control white clovers (Trifolium repens) without harming the grass in your lawn. To help control white clovers in a lawn, you can apply fertilizer, dig up the plants or spray the lawn with a selective weedkiller.
A lawn infested with white clovers is probably low in nutrients. Grass grows poorly in low-fertility soil but white clovers thrive and out-compete the grass. Fertilizing the lawn improves the growing conditions for grass, which can then grow strongly and overcome white clovers.
Fertilize the lawn with 1 pound of actual nitrogen per 1000 square feet when the grass is actively growing. Evenly apply the fertilizer using a lawn spreader, and water the lawn afterward. Apply fertilizer four times per year over the growing season at evenly spaced intervals.
Digging Up Clumps
White clovers grow in wide, shallow clumps with a central tap root. Digging up the plants and removing their roots helps control white clovers but has no effect on the grass.
Grasp a clover clump in one hand, exposing the base of the plant. Push a trowel deep into the soil next to the plant's base, and lever the trowel upward. The clover roots should lift out of the soil. Remove the other clumps in the same way, and dig up new clover plants as soon as they appear.
Sow grass seed on any bare patches of soil that remain after removing the white clovers.
Quinclorac, triclopyr, aminocyclopyrachlor and fluroxypyr are of the some broad-leaved weed herbicide ingredients that control white clovers. Broad-leaved weedkillers rarely harm grass, though they can be harmful to ornamental plants as well as people and pets. The best time for controlling white clovers with herbicides is when they're small and actively growing.
Water a dry lawn 24 to 48 hours before applying a herbicide. Put on long pants, a long-sleeved shirt, shoes, socks, safety goggles and gloves, and cover plants growing near the lawn with cardboard before applying a ready-to-use broad-leaved weed herbicide. Evenly spray an herbicide containing 4.85 percent 2,4-D, 1.61 percent quinclorac and 0.45 percent dicamba on a still, dry day when temperatures are below 90 degrees Fahrenheit.