If physical removal is attempted, take care to dispose of all plant fragments as Virginia buttonweed can reproduce from small pieces of the stems or roots.
Virginia Buttonweed is a spreading perennial weed with opposite leaves that often have a yellowish mottling due to the presence of a virus that grows in close association with this weed. The plant has an extensive root system and develops underground rhizomes (rhizomes have been found as deep as several feet below the surface). Buttonweed reproduces by seed, roots and stem fragments. Its prostrate growth habit enables Virginia buttonweed to survive low mowing. Virginia buttonweed seems to proliferate in moist or wet areas, often in irrigated lawns and is a very troublesome weed of lawns throughout the southern states.
Virginia buttonweed is one of the most difficult-to-control broadleaf weeds found today in turfgrass. Hand removal of Virginia buttonweed is often ineffective, because any stem fragments or rhizomes left behind can produce a viable plant. Care must be taken, however, to remove as much root as possible to maximize control. Check these areas frequently the entire summer and remove any new plants that emerge. This must be repeated again next summer for complete eradication.
An alternative to hand removal is to spray with Roundup, which will damage the turf and may create a dead spot in the turf for other weeds to emerge, or use a selective broadleaf spray that contains 2,4-D, dicamba, and MCPA or MCPP. Care must be taken to ensure the one selected can safely be used on the type turf in the lawn. Repeated or sequential applications will be necessary for complete control.
There are several professional grade post-emergent herbicides that can be applied over an extended period that have shown success at controlling Virginia Buttonweed. Steps should be taken to control this noxious weed as soon as it is discovered.