Known by many names, goat head thorns are a real nuisance. They can be greatly controlled with some simple practices and persistence. We’ll show you how!
When we were kids, we just called them “stickers.” If you got into a patch of them while barefooted, it was a very unpleasant experience. They were also very hard on bike tires and we had to repair many a flat after an encounter with what was also known as “goat heads.”
Their botanical name is Tribulus terrestris. Even that name sounds bad! “Tribulus” refers to an ancient weapon called a caltrop. These multi-spurred weapons could inflict a lot of damage and if they were spread on the ground, one spike would always be facing up. Just like these weeds.
Whether you call them Goat Heads, Puncture Vine, Caltrop, Bullhead, or Sandbur - they all mean you need to take measures to control them. While they aren’t spread by the wind, it can still be trouble if neighboring areas have Puncture Vine infestations and the burrs are transported to your property by animals, footwear, equipment, bike, or vehicle tires.
These weeds are well adapted to grow in neglected, disturbed, or bare soils. They have a very low, mat-like profile, so they are not easy to see until they are actively growing or blooming. Because they can easily “hitch rides”, they can show up in unexpected places.
That’s not all. The seed is viable for about 7 years, and a single plant can produce up to 5,000 seeds! If that wasn’t enough, those seeds germinate throughout the summer months. So, ongoing vigilance is needed to control them.
There is some good news in all this. Before the weeds go to seed, they are relatively easy to control. Small areas can be hand-managed by pulling the small weeds before they form the thorned pods. Larger areas can be sprayed with your favorite herbicide. Simple hoeing or hard raking can do the trick as well. If an area had mature plants the season before, pre-emergent weed controls can be used.
If you were late in your control efforts, and you have sizable plants with plenty of the thorned pods on them, the best thing to do is to hand-pull them. That’s right. Using gloved hands (and wearing good work shoes, not “flip-flops”), grasp the center of the plant, where all the branches emanate from. There aren’t any thorns there. You can “peel” back the arm of the weed to reach the center. If there is a bad infestation, you’ll have overlapping weeds to contend with. Then gently but firmly lift straight up, pulling out the central tap root. The entire weed will lift away. Because the plants cover a lot of ground, you can clear a lot of ground quickly. This will be the worst of it, as subsequent encounters will take less effort. Dispose of each plant in the trash or burn barrel. DO NOT compost them. You are asking for trouble if you do!
If you find the weeds quite late in the season, when they have yellowed and the pods are falling off, pick up what you can to help eliminate the further spread of the pods. You can use carpet or rubber kneeling pads and like material to get the thorns to stick to so you can pick them up. Make a note of the area, and in the following season, you’ll really need to control any resulting infestation.
Not all controls for this pest are reactive. You can be proactive as well. Since they thrive in bare, disturbed, or neglected soil, and there is little competition from other desirable plants, you’ll need to create competition. Plantings of groundcovers or placement of deep mulches are both great ways to put the odds in your favor of controlling goat heads. They don’t do well in shade, so deprive them of sunlight!
If you’d like to know more and get even more specifics, here is a great fact sheet on Puncturevine:
Hey, Dirt Farmer Jay here from DirtFarmerJay.com. Do you have these stickers in your yard?
Boy, they can be really brutal and really scary, but they don't need to be. Hey, stay tuned and
I'll tell you how to win the war against these little devils. Hey, Dirt Farmer Jay here from
DirtFarmerJay.com. When we were kids, we used to call these little things stickers. Well,
they come under a lot of different names. All of them sound really bad because this is one bad weed.
We knew them also as goat heads. They're also known as caltrop and also sandbur puncture vine.
And here's your Latin lesson for the day. Their botanical name is Tribulus Terrestris.
Something you might find interesting is that first part of that botanical name, Tribulus,
actually refers to the ancient medieval weapon of a caltrop that was laid on battlefields
that horses or foot soldiers would step on and lame them. Ouch! Bad stuff. And you can see how
they got its name. First, I'm going to tell you all the tricks this weed has up its sleeve
to make sure it thrives and it gets in places you wish it didn't. The second thing we're going to do,
I'm going to tell you how to use its own tricks against it to be able to control this and win the
war against the caltrop. All right, here's at least six characteristics this plant has that
allows it to infest new areas. Number one, the amount of seed it produces. The individual plant
will produce anywhere between 500 and 2,000 seeds per plant. So you get an area, you do the math,
you can quickly overwhelm an area. Number two, that seed is viable for up to seven years,
meaning that it could be transported or dropped in the area the original infestation happened,
and it can wait up to seven years to sprout to life. How's that for putting its odds in its
favor? It's also easily transported because of its caltrop multi-pronged shape that gets
stuck in footwear, tires, farm implement, hooves of animals, the fur of cats or dogs,
and then is combed off or groomed off another area or broken off, and therefore the magic starts all
over again. Here's another thing, another trick up its sleeve. Its growth habit is cross straight.
It is very flat. It's a mat-like plant emanating from a single crown in the middle, and it radiates
out from there very, very flat, and you can't really see it from a distance until you walk up
on it and look down on it, so therefore it can be very stealthy, get a foothold, and so, you know,
and get a jump start. The next thing that is really against you is that it germinates all
season long. Many plants really germinate early in the growing season when the warmth comes on.
This plant has the ability to germinate throughout the growing season, so you may control in one area,
pull a bunch, burn them off, whatever it might be, and then you come back and find the same area has
new growth of new plants because they've continued to germinate through the warm season. This plant
thrives in areas that other plants don't do well in. Neglected areas, disturbed soil, someplace
that's really sunny, sandy, and even they'll thrive in rowdy conditions due to the taproot they throw
down to pull up needed soil, and even the leaf structure, which are very small little leaves,
don't lose a lot of moisture, so they become very well adapted to thrive in areas that desirable
plants don't. So what do you do? So let's start with the idea that you've walked around your property and
you find green plants that are growing right now. If they are small and they do not have yellow
blooms on them, they can be controlled with just regular old weed killer of some kind. It's up to
you if you want to use an organic control, you want to flame them with a weed burner, you want to use
a 2,4-D or a glyphosate typing, that's your decision. But what I'm saying is the plants will kill off
very easily using standard herbicide type of approaches or torching. So you can burn off the
baby ones. If they're further along and they're getting sizable and you're seeing little yellow
blooms all over them, chances are they've already started to go to thorn. And you'll see the seed
pods, which actually will fall apart when they're dry or even just semi off the plant, they'll start
to fall apart and that's where the seeds are contained in and get transported. So at that point
to minimize seed drop and to get them out of the ground, you're going to pull them at the center
of the weed right at the crown where all of the branches come together. You can actually use an
ungloved hand because the thorns are not there, but heck you're working in a patch of them. So I
would use full shoe wear gardening gloves and you're going to reach and tug that out or cut
the tap root. Carefully lift the plant up and if it's intertwined with others try to separate it a
little bit so you're not dragging the thorns off and dispose of it. Do not compost it. Don't throw
it anywhere else. You know you say I'll handle it later. It either needs to go in a burn pile
or burn barrel and be burned or it goes in the waste stream in a trash can and gets hauled away.
You don't want those babies coming back to life. Okay so that's the first one. If you have or the
baby plants, ones that are actively blooming and are creating thorns. The third thing is if you
have a dried plant that has gone through its cycle, it's pretty much lost most of the thorns,
but if the thorns are still in place you can do a couple things. You can pull the plant
and collect the seeds by hand. One agricultural publication suggests if you're also growing
pumpkins and you've got old pumpkins rolling pumpkins and picking it up or a piece of carpet
or rubber kneeling mats, something to get as many of those you can and dispose them or pick them out.
That's great. Get rid of them. However, if they've already been dissipated or they're down in the
soil, now your game plan is the following season and what you do is journal that, mark it, flag it,
whatever it takes to remember where these infestation areas are and when they start up the
following season. Then that time you would again use the weed controls that we talked about a
moment ago, which includes herbicides or flaming or actual light hoeing does a lot. You can take
out thousands of these little weeds just by using a slider hoe of some kind and cutting them off
and just hassling them as a very young plant. That'll get you a long way along in controlling
these and then it's an ongoing game of monitoring because of the inbound transport
that occurs where things are being brought in by animals and people to your property. If you really
want to be a super geek and all things puncher buying, here's a great technical paper that Utah
State University put out. I've provided the link in the description below. You just click on that
and go and download this great paper and boy you'll be the head of the next backyard barbecue
having everything you need to know about your puncture vine, how it grows and how to control it.
You know another thing that happens if you have a lot of weeds around your yard and they are not
this kind of weed, the puncture vine, here's a video that you can watch that are three great
uses for weeds that really you don't just have to throw them away, you can put them to use
in your yardscape. And while you're at it, check out this other video that YouTube thinks is perfect
for your interests and we think you're going to enjoy as well. Hey until the next time this
is Dirt Farmer Jay from DirtFarmerJay.com enjoying a barefoot walk through the park.
