THE ISSUE:   Puncturevine

Puncturevine (Tribulus terrestris) commonly known as goathead is a kid’s flat tire waiting to happen. This annual invasive plant can form 8-foot diameter dense mats, competing with crops and native plants. The destructive spiny burrs can injure livestock, pets, humans, and can damage recreational gear like bicycle tires. It invades pastures, rangeland, roadsides, waste areas, cultivated fields, and other disturbed sites. 

Its greenish-red, branched stems are covered with fine hairs. Leaves consist of 3-8 pairs of opposite, oblong-lanceolate leaflets, each being 5-15 mm (about 0.59 in) long and 3-5 mm (about 0.2 in) wide. The upper surface of the leaflet is darker than the underside. The small, yellow, 5-petalled flowers grow solitary in leaf axils and develop into a gray to yellowish-tan, circular, woody burr that split into 5 sections, each with 2 stout, divergent spines. Puncturevine is native to the Mediterranean and is adapted to dry, loose, sandy soils. Its long narrow tap root helps it to survive in dry soils. 

Integrated Pest Management (IPM) Options:  

• Prevention – Learn to identify this plant. Never transport unknown plant material. Always remove and properly dispose of all seed and plant materials on vehicles, clothing, shoes, and pets before you exit or enter outdoor recreational sites. 

• Mechanical – Hand-pull or dig up prior to seed formation in the spring. Make sure to remove any spiny burrs from the ground. Continue to remove plants throughout the summer. 

• Chemical – Post emergent herbicides have been effective at controlling puncturevine. Many restricted and non-restricted use herbicides are available, for more information visit https://pnwhandbooks.org/ then search “puncturevine” in the weed section. Always read and follow herbicide label directions!

Tom Jacobsen, University of Idaho Extension Agriculture Educator in Fremont County. (208) 624-3102
[email protected]