Goathead (Tribulus Terrestris, USDA plant hardiness zones 4–11, although found in Southern Europe) is an invasive weed plant to most North America, especially the Southwestern and Rocky Mountain states.
Goatheads are well known for their seedpods, which are rough and spiky enough to damage bike tires and shoes and injure those wandering in bare feet. The weed can be known as puncturevine, caltrop, bindii, devil’s thorn, devil’s eyelashes, devil’s weed, cathead, and tackweed.
Goat heads are perennials with robust roots that often re-seed after being pulled by hand. To seed, goat heads do not need to be tall. Their thorny seed burrs can be dropped as they creep beneath your mower height.
Goat heads are prolific seeders, and their burrs can be found all over your yard. Fighting goat head weeds requires patience and understanding that dormancy isn’t how to get rid of goat heads in the fall and winter.
Any surviving roots grow back vigorously in the spring. Those burrs also sprout and mature into goat head plants in the spring. (Learn How To Kill Mushrooms Without Killing Grass)
In our guide, you can learn the best ways how to get rid of goat heads without killing grass.
How to Kill Goat Heads
If you’ve ever stepped on a goat head and suffered the pain of the sharp burr, you’re not alone. Once is enough, and can lead you to want to get rid of all the goat head weeds in your yard. Worse, if goat head isn’t dealt with quickly, they take over lawns and gardens.
They don’t stop reseeding even when you mow them. Goat heads can grow low and drop burrs at the soil level. Here are some key ways how to get rid of puncture vine.
Goat Head Weed Killer Spray
The perennial weed goat head has a deep taproot. Hand-pulling is usually useless in eradicating goat heads because sections of the root that break off in the soil immediately regrow. To get around this, As a result, use a weed-killer spray that destroys goat heads as soon as they develop.
RoundUp and other Glyphosate-based weed herbicides effectively kill goat heads in gardens. Just be careful not to use your pump sprayer in windy conditions or around desirable plants with glyphosate, as it kills any plant it comes into contact with.
Use a selective weed killer to kill goat heads without hurting the grass in your yard. Allow 1–2 weeks for the herbicide to take effect. While the top of the plant may droop within hours, the weed killer takes time to kill the plant down to the root.
Weed killer sprays have one flaw: they don’t kill weed seeds. The stinging burrs that goat heads shed are their seeds, which will germinate quickly if left unchecked and can still puncture bicycle tires long after you have killed other parts of the plant. A propane weed-burning torch is a fantastic weed-killing instrument to eliminate invasive species of weeds. They’re like a mini-flamethrower, powered by a propane tank and ideal for torching weeds.
A flame weeder will not only kill the goathead plants, but the propane flame will destroy all the seeds, including pesky goat head burrs. Use caution when using a propane weed burner, especially if the lawn is dry or the weather is windy during a hot summer. To guarantee the goat head plant is eliminated, use the flame weeder in a controlled manner and carefully burn the entire plant without harming your desirable plant next door. (Read Best Way To Clean Up Pine Needles)
Remove Dead Weeds
Now is the time to remove the dead mature plants of the goathead weeds you sprayed or torched. You can get rid of the goat head weeds by hand weeding or raking. This helps to guarantee that no seeds from dead plants fall to the ground and clear the land for the grass or other plants to grow. Keep all your dead weeds in a plastic bag to avoid seeds falling to the ground and starting new growth.
Use Landscape Fabric and Mulch
It’s time to keep goat head weeds from returning once you’ve killed and removed them from your garden. Most weed seeds must be within 1–2 inches of the surface to sprout. Lay down water-permeable landscaping fabric in your garden and cover it with a 3–4-inch layer of mulch to prevent any residual seeds from sprouting.
The landscaping fabric physically prevents goat heads from springing up through the mulch while still allowing water and nutrients to reach your garden’s soil. Over the landscaping fabric, you can use pebbles, synthetic mulch, or even newspaper as a ground cover. However, because goat head thrives in arid areas, many gardeners restrict it using desert-friendly rock and gravel groundcovers.
If you lack any landscape fabric, you can eventually use an old carpet to break down. But, in the meantime, it does an excellent job of stopping undesirable plants grow.
How Do You Get Rid of Goat Heads Naturally?
Use a Pre-Emergent Herbicide
Even the most thorough weeding and burning will leave some goat head, sand spurs, and burrs.
This is problematic in grassy yards, where your landscape fabric and mulch aren’t workable solutions. Luckily, before looking at natural ways, you can see how a pre-emergent weed killer helps.
Apply to your lawn in the early spring, late March, or early April. Then, these get to work and kill seeds before they can produce them fully and germinate. Use this to keep mature goat heads returning after removing them.
Pre-emergent weed killers prevent all seeds from sprouting; therefore, don’t use them for 4–6 weeks after sowing grass or 3 weeks before seeding your lawn. There are several natural ways how to kill goathead weeds. Here are some of the best you can find.
First, verify with your local fire department or city for usage rules. For example, some require a burn permit, while others do not. (Learn How Long Are Zucchini Good For)
Vinegar to Kill Goat Heads?
Although vinegar will make goat heads droop, a homemade weed killer produced with vinegar will not kill the weeds at the root. Mixing horticultural vinegar with a small portion of dish soap is advisable. The soap helps vinegar stick to the goat head leaves.
Some gardeners also add salt, which can change the soil composition, stop other plants from growing, and impact grass development.
Use Puncture Vine Weevils
Puncture Vine weevils (Microlarinus lareynii and Microlarinus lypriformis) help eliminate these weeds. Microlarinus lareynii, a seed weevil, lays its eggs inside seedpods, whereas Microlarinus lypriformis, a stem weevil, lays its eggs on stems. The larvae feed on the plant and seed pods, thus destroying them.
In the treatment goathead weeds, these weevils work best when used together. You can get them from biological control suppliers, yet they are not recommended for small gardens as they may not survive in your region. (Read Running Sprinklers During A Freeze)
Goathead Characteristics and Seedpods
Goathead is a low-growing plant with a deep taproot. Its taproot is long and deep, growing in arid and compacted soils. Orchards, gardens, pastures, and lawns can all be infested.
This plant is an annual summer broadleaf that spreads through a central taproot. Its hairy leaves are separated into four to eight leaflets that grow opposite each other. It has half-inch yellow blooms.
Seedpods are clusters of five spiky burrs and comprise up to five seeds. Goathead seedpods are green at first, then gray or tan. Then the goathead seedpods become stiff.
Goathead Life Cycle
A single goathead plant can yield 200 to 5,000 seeds per year. Seedpods can lie dormant in the soil for up to five years, waiting for the right conditions to sprout. While the seeds require adequate soil moisture and warm temperatures to grow, the plant can tolerate most climate conditions in North America with freezing temperatures.
Season-by-Season Steps to Get Rid of Goat’s Head Stickers
Late Winter or Spring
Apply a pre-emergent weed killer like Surflan, which contains oryzalin and trifluralin, from March through June. Try mixing 1/2 cup Epsom salts and 1/2 cup vinegar in a gallon of water and spraying it thoroughly for a home remedy weed killer. (Read Weed B Gon Instruction)
Large infestations should be swept with a gas weed burner, staying near the ground to burn off the roots. Follow your burn with a weed killer that will kill the underground roots. Note: A weed burner eliminates the need to rake.
Spray weed killer on them in full sun as soon as they appear. Spray and cover for a week with a sun-blocking tarp or carpet. When the plants become yellow/brown, remove the covering and go to the next step.
With your upright weeder, dig out the goat’s head plants. You can remove little plants by hand if you are fit and wear protective gloves. Then, grab the entire plant and slowly pull sideways to get the entire root system out. Straight-up pulling frequently snaps the plant off, leaving the roots behind.
Rake the area, removing all goat’s head debris. Finally, sweep the cleared area for thorns. Remember to trash or burn goat’s head, weeds, and thorns. If you don’t, they reseed.
Instead of insecticides, plant wildflowers and other ground coverings to smother the goat’s head plants. (Read Orange Lily With Black Spots Guide)
Fall and Early Winter
The first freeze kills the goat’s head plant in cold climates. As previously said, the plant aggressively reseeds, so remove your property of thorns, stems, leaves, and roots. Please put them in the garbage or burn them.