Puncture vine (Tribulus terrestris) or goat head is a weed destructive to people and animals. It has runners that spread up to 1.8 m (6 feet). The round, sticky seedpods cause painful injuries in humans, pets and livestock. Once you identify the puncture vine, controlling this weed is possible by natural or chemical methods.
Identifying puncture vine
The puncture vine has small leaflets and 1.2 cm (1/2 inch), yellow blooms. The hard, spiny burrs contain seeds that arrive after the flowering ends. Puncture vine leaves resemble mesquite leaves and form mats around the lawn area. Burrs may grow as large as 1.2 cm (1/2 inch) wide. The leaves are in a cotyledon fashion with two true leaves.
The round, sticky seedpods are burrs that cause painful injuries when stepped. The burs readily grab hold of an animal's coat, causing matting and tangling of the hair. They are difficult to remove and it may be necessary to cut them out with scissors. Gardeners may also get a painful surprise by grabbing a burr by mistake. The spikes are stout enough to puncture a tire, thus making it necessary to eradicate this weed in your lawn.
Natural and biocontrol
Wear heavy work gloves to rid the puncture vine naturally. The gloves protect your hands from the sharp burs. Pull the plants out by the roots with your gloved hand when the soil is moist. Inspect tires, shoes, bicycles, wheelbarrows and incoming hay or livestock for the burrs to prevent them from spreading on your land. The Microlarinus lypriformis and M. lareynii weevils feed on the seeds and are effective in controlling this annoying weed. This type of control is best in areas where there are large amounts of the puncture weed. The weevils won't survive for the next year if they do not have a plentiful supply.
Puncture vine seeds are viable for up to 20 years in soils. Chemical control is an effective way to rid your land of this plant. Use a pre-emergent herbicide in the spring before the weeds germinate during the summer months. Purchase an herbicide that contains trifluralin or oryzalin. Selective herbicides are effective in ridding lawns of this weed if it is widespread. Read the label to ensure it kills puncture vine.