I have recently had questions about controlling white clover in lawns. The following is information on this pasture legume that can become a weed problem in turf.
White Clover is a low growing sloloniferous legume that often infests cool season turfgrass. Although not unattractive, it is viewed a weed because it is short lived and seed heads attract bees. Identify by the compound leaves composed of 3 unstalked leaflets less than 1 inch long with white crescent shaped marks. Blooms will be 1 inch diameter white balls starting to appear in May and producing seeds that can last for many years in the soil. White clover is most prevalent in turf receiving limited nitrogen fertilization and is more of a weed problem in cool, moist years. Low mowing also favors white clover.
Control white clover in cool season turf by increasing nitrogen fertilization, cutting higher, and managing for a dense grass stand. Many broadleaf herbicides are effective on white clover including products containing triclopyr (Turflon ester, Confront, other combinations); clopyralid (Lontrel, Confront; clopyralid is not for use in residential turf); quinclorac (Drive – can also be used on new seedings), fluroxypyr (Spotlight, Escalade ), and combination broadleaf products that contain mixtures of 2,4-D, dicamba, MCPP, or MCPA (Trimec and many others; note that any of these ingredients alone will not provide adequate control). Newer combination products such as Q-4, Speedzone, and Powerzone will also control clover.
Gordon Johnson, Extension Horticulture Agent, UD, Kent County