Photo by Jack Kelly Clark.

Photo by Jack Kelly Clark.

Puncturevine  (Tribulus terrestris)

“B” Rated Noxious Weed

Puncturevine aka “goatheads” produces many burs with sharp spines that can injure humans and animals, and is well known for puncturing bicycle tires. Small populations of puncture vine can be controlled by hand pulling before or during flowering. This works best in moist soil. Once the burs begin to develop, you will definitely need heavy gloves for hand pulling. Diligent hand pulling can be very effective.

Learning how to identify puncture vine seedlings is recommended so that you can remove them before they flower. Here is a photo of a puncture vine as a seedling:

 Photo by Jack Kelly Clark.

Photo by Jack Kelly Clark.

Punturevine reproduces by seeds contained within the "goathead". Stems and leaves of the plant are covered with hairs. Leaves are mostly 2/17 to 1/5 of an inch (3–5 cm) long when mature, finely divided into three to seven pairs of leaflets, and opposite to one another along the stem. It is a mat-forming, broadleaf plant with an extensive root system. Flowering takes place from March through October. Flowers are bright yellow, about 1/5 to 3/5 of an inch (5–15 mm) in diameter, and are produced singly where the stem and leaf stalk meet. They open only on sunny mornings, except in shady areas.

"Traditionally, landscape maintenance companies and homeowners have used various herbicides to control puncture vine in and around commercial and residential landscapes. Pre-emergent herbicides containing oryzalin or trifluralin applied in spring will kill seedlings as they germinate during summer. Selective herbicides can be used in situations where puncture vine has invaded lawn areas. When correctly applied, a selective herbicide will kill puncture vine (and other broadleaf weeds) but not harm the grass. There are many selective and pre-emergent herbicide products available. Some of these are not labeled for use on puncture vine, so always read the product label before buying." - Backyard Gardener https://cals.arizona.edu/yavapai/anr/hort/byg/archive/managingpuncturevine.html

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