FAQ

     I am writing in response to your question on Puncturevine (Tribulus terrestris).  This is a pernicious annual weed that has preyed upon many an unfortunate child’s’ bike tire.  Because the weed is an annual, it completes its life cycle in one growing season (seed to seed).  Yellow flowers cover the ground hugging plant throughout the summer months.  These flowers, once pollinated, produce those notorious spiny bur-like fruit which in turn give way to next problematic plants.  The seeds of puncturevine can remain dormant in the soil for up to 5 years. 

The good news is that because the weed is an annual, control is possible with persistence.  During the late summer and fall months, removing the plants while the seeds are still intact offers the best control.  Try to remove as much of the seed supply from the site as possible.  The following spring, physically remove the small seedlings as they appear.  Using a good hoe or shovel early on proves to be very effective against annual weeds. 

There are chemical control options as well.  A few pre-emergent herbicides, such as products containing trifluralin, oryzalin, or benefin can provide partial control of germinating seeds.  Post-emergent herbicides such as 2,4-D and glyphosate may also be used to control the plants once established.  2,4-D is a widely available broadleaf herbicide used to control weeds in lawn settings.  Be careful not to spray 2,4-D if the temperatures are going to be above 85 degrees.  Glyphosate is the active ingredient of Roundup and other non-selective herbicides.  Non-selective meaning it will kill almost any plant with green tissue, so care needs to be given around other plant material.  As with all chemicals be sure to read and follow the labeled instructions