Puncturevine (Tribulus terrestris)

About Puncturevine:

Puncturevine is a summer annual plant that creates a dense mat along the ground and is considered a noxious weed, meaning the plant can be harmful to the environment and animals. The spikes that this weed produces are so sharp that it can puncture bicycle tires, hooves, paws and feet. The leaves of this plant produce saponins, which is toxic to livestock and more specifically sheep when consumed in large quantities.

Family: Zygophyllaceae Family

Puncturevine Scouting and Prevention:

As a seedling, Puncturevine has thick, oblong, green leaves with a grayish backside and a small indent at the tip of the leaf.

A mature Puncturevine has hairy, oval shaped leaves that grow in pairs on either side of the stem. It produces yellow flowers that grow in the leaves axils and are about 1 and a half inches wide. The flowers start blooming from March until October and only open on sunny mornings, unless they are in the shade. Puncturevine also creates tough, sharp fruits/burs that carry the seeds. They have 5 sections and are gray, yellow, tannish colour. The overall reach of one stem is about 6 feet during the summer months with several green to reddish brown branches protruding off of it.

Common locations

• - Hot and dry conditions
• - Where there is high soil compaction
• - Orchards
• - Pastures
• - Turf

Prevention

Pre-emergent herbicides applied around the beginning of April can terminate Puncturevine seedlings as they start germinating. You may have to reapply at the beginning of April for several years for optimal control and prevention. Products that have benefin, oryzalinIt or trifluralin give partial control to the seeds that are germinating. These pre-emergent herbicides must be applied to designated areas in the late winter to mid-spring, which is before the germination process begins.

Puncturevine Control:

The best way to make sure this plant does not come back as heavy as the year before is to reduce the number of seeds in the soil. This can be done by removing the plant before it has time to produce seeds or before it flowers in March. Puncturevine does not disappear; you will have to continue removing the plant for several years for full eradication.

Cultural Control

A good way to deal with Puncturevine is by pulling it out by hand. Make sure if you decide to manage the weed in this way, you wear gloves to protect your hands from the prickly burs. Hoeing Puncturevine is also very productive to cut the taproot of the plant. Make sure when removing this plant that all stray burs are picked up. This is an important step in culturally controlling this plant due to the fact that the burs are the seeds of the plant. Keeping an eye on the area where you removed the weed during the spring and into the beginning of summer and pulling out Puncturevine if it decides to regrow will greatly reduce the growth for next year. Screening out light with 3 inch thick mulch on gardens is also effective. However, if the burs fall on mulch, Puncturevine can start to grow again. Planting a competitive, desirable plant in the area where the weed used to grow, or could potentially grow in the future will reduce the resources for the weed.

Chemical Control

Herbicides can also be a productive way to manage Puncturevine if it is applied while the plant is still small and/or young. Products that have 2,4-D, dicamba or glyphosate can be effective on this weed. 2,4-D and dicamba can be used on lawns and won’t hurt the desired grass. However, it is damaging to broadleaf plants. The best way to manage the unwanted spread of this weed is to spray the herbicide close to the weed when there is limited to no wind in order to minimize the drift. As for glyphosate herbicides, it is deadly to all plants and therefore should only be used for spot treating.

Latin / Alternative Puncturevine names:

• - Tribulus terrestris
• - Goat head
• - Caltrop

Additional Puncturevine Resources