Those of you with substantial yards/acreage need to get out there and either pull/poison the goathead plant while they are pre-emergent and relatively small.
You don't want the giant mats to develop with hundreds of seeds dropping off ensuring a bumper crop next year.

 I found 2-4D herbicide concentrate at 15% or better does a good job (various brands available) and I usually mix it with some 43% or better of glyphosate when clearing large areas of other weeds like thistle and kochia
My hard work last year on my land made a big difference this year, and only had a small amount to contend with over the past few weeks while working my land.

https://en.wikipedia.org/wiki/Tribulus_terrestris





Here's a PDF to help you identify what other weeds you may have lurking in your yard.

https://idahofirewise.org/wp-weed_handbook_2011.pdf

I never knew what goatheads were until we moved here 3 years ago. It didn't take me long to decide that I hate their habit of hiding in the bathroom floor mats.

Not sure where you are coming up with your numbers.  Here is the label for a popular 2,4-D Herbicide:

Attached File


Goatheads are easy to kill but they are persistent little bastards so the drop-dead concentration of the above is a 0.75% Spray Concentration or 0.3 cups / gallon of water.  If they already have yellow flowers, you are way too late and that crop is in the ground and you will be dealing with it next year.

Yellow flowers are a sign of post emergent activity, and are an indication of the plant beginning the seed cycle.
Once it has the green seeds on there....your gonna need to manually pull the plant to prevent the seeds from getting into the soil.
Whats amazing about the plant...if the green seeds are present, and you spray it....the plant will use the last bit of life to mature the seeds to viability.

Lot's of folks buy their stuff at HD or Lowes, and may not read the labels for concentration levels.

2,4-D levels in many of the brand-name pre-mixed or ready to use products are generally much lower like, 10-15%.....so as a baseline, I recommend  using a product with at least 15% or better for effectiveness.

My go-to is the Amine 400 concentrate on goat heads, and hard-to-kill weeds and brush, in a mix with glyphosate, as TSC usually has it in stock.

But the biggest take-away here is .....don't be complacent !!

Get out there and pull what you can, spray what you can, and make the effort to eradicate these bastards !!

Another reason to hate Idaho!

Goatheads, aka "Puncture Vine" is a preview of hell.

I use 2-3 ounces of super Round Up and the same of 2,4D, with 1/2 oz. of wetting agent and 1/2 oz. of blue die per gallon with a backpack sprayer.  Spray 'em when they're little.  Big ones are easy to pull once you find the main root.  A weed puller or small shovel gets them out.  Don't go back in the house until you pull the stickers out...I leave my Goathead shoes outside as wife is a native Idahoan and a very good with a rifle or shotgun.  

Is the blue die to tell which ones you've sprayed?

The blue die comes from the wetting agent I use in my mix and "yes" it shows your spray pattern.