The Ohio State University

Home LandscapeNotes There are large patches of white clover on sports fields and home lawns that seem to be on the increase. This could possibly be due to a decrease in nitrogen fertilizer applications and/or broadleaf herbicide applications? White clover is also flowering right now, which makes it more noticeable.

Weed Identification: White clover (Trifolium repens L) is a low growing, creeping perennial weed that roots at the nodes. Leaves are made up of three leaflets often with pale inverted v-shaped markings on each. Flowers are white or tinged pink.

White clover is a common weed on lawns and sports turf. It can survive in somewhat adverse conditions (low soil fertility, wet soils, close mowing) and so is commonly seen on home lawns, sports fields and other low-medium maintenance turf. The problem with clover on sports fields is that is does not offer a uniform playing surface for the athlete or the ball. It also dies-back in winter, sometimes when sports are still being played. White clover flowers can also attract insects like bees. In home lawns the main problem with white clover is visual uniformity and aesthetics. While some home owners may embrace species diversity in a lawn, most would not welcome aggressive weeds like clover that can sometimes take over. In low maintenance turf white clover is usually tolerated because it is "sustainable" in that it can fix its own nitrogen. For that reason, it is sometimes found in low maintenance turf seed mixtures.

Control Options:

* Cultural: The best defense against any weeds in turf is to grow dense, healthy grass. This includes mowing at the correct height for the species, fertilizer applications, relieving soil compaction, over-seeding thin or bare turf, and providing water when turf becomes drought or heat stressed. A sound fertility program is important to give turf a competative edge, since clover can grown in low N soils.

* Mechanical - good old hand-pulling! This would need to be carried out aggressively as the stolons will continue to grow if not all of the weed is removed.

* Chemical: Preemergence herbicides are not really a defense against clover as it spreads mostly by stolons. Selective systemic broadleaf herbicides are the preferred chemical control option. Many of the herbicides can cause phytotoxicity if applied to stressed turf in hot weather. For that reason, watering the turf or waiting for rain to bring it back into good growing condition before applying herbicide is recommended. However, since white clover is a perennial, best control is achieved with a fall application.

For a guide to herbicides that are available in turf and some recomendations for choosing the best product to control a certain weed, you can Download this.pdf file.

Posted by Dr. Dave Gardner & Pam Sherratt