Q&A for How to Get Rid of Thistles

For thistles, I recommend using a white vinegar spray to kill them.

Thistles are prickly, but they aren't poisonous to humans. If they were thistles, the stinging should go away on its own. It's possible that you actually removed stinging nettles, which are commonly confused for thistles and can cause a lingering stinging feeling. The hairs on stinging nettle release an irritant when they're touched. The feeling should go away in a few hours. If you develop a rash and it starts itching, you may be allergic to nettles. See a doctor if the issue doesn't get better in a few hours.

This may curb the problem temporarily, but it's dangerous and the thistles are very likely to grow back the following year.

It's complicated. It can take years to totally kill the root system. If the plants are young and you can physically lift the roots out, then that's definitely the way to go. But the premise behind snipping the plants at the base makes sense. Theoretically, cutting the plants back over and over will put a strain on the roots, and if you can't remove the root system entirely, that's not a bad way to go. This is why mowing the thistles before the plants get momentum during the growing season is effective.

Fire will definitely kill any seed pods. But this isn't going to be a solution to your problem. The fire won't kill the roots and your thistles will just reappear the next growing season. If you're just talking about burning the dead plant matter after you remove it to make sure the seeds don't spread, that's totally fine.

It depends on how deep the root system is. If the thistles are young, this may work. Unfortunately, mature thistles can have roots that go up to 20 feet deep, and the Roundup won't kill those root systems off.

You can buy them online. There are pest management companies out there that will ship you the bugs.

Yes, you can burn dead thistle. Place the weeds in a pile, let them dry for a day or so, and then ignite them with an accelerant. This is a good way to dispose of the plant and any seeds.

Make a salt water solution of 25% salt. Dissolve it in hot water to be sure all of the salt is dissolved. Clip the thistle about 2/3 inches above the ground and put a small amount of the solution into the center of the stub that is left. This will kill off the root system in total and make it so it will not come back.

You could, but that alone won't solve the problem, and you should follow the steps in the article.

Some commercial applications (such as Roundup) will kill rhizomes if applied to the leaves.

After you have killed the thistle, keep an eye out just in case it grows back. I would recommend pulling the roots up to decrease the chances of this.

Advanced Turf Solutions has a product just for creeping prostrate juniper.

Cut the thistle with shears as close to the ground as possible and leave on the surface for the sheep to eat when the cut parts dry out. Some will regrow so repeat the procedure. In time, post two or three seasons, none will grow.

The most effective herbicide is also the most toxic to surrounding plants. A systemic herbicide will kill the thistles and keep them from coming back. If you don’t mind killing the surrounding plants, this is the way to go. Pick up a systemic weed killer that contains glyphosate, which is the most efficient ingredient at permanently wiping out thistles. Apply the herbicide according to the directions on the packaging and try to apply it in Spring or early in the growing season to wipe out the thistles before they get a chance to establish themselves. Keep in mind that the glyphosate in a systemic herbicide will likely harm any nearby plants, so don't use it to knock out thistles in your garden.

There are actually a few types of insects that will feast on any thistles in your yard, which can weaken and kill the plants. Insects can be tricky to attract or find, but you can buy some of them and introduce them to your yard. They'll start snacking on your thistles and can help you eradicate them. Pick up a few hundred stem-mining weevils and release them near your thistles. The adult bugs will eat the thistles and plant larvae inside of the stems. Once the larvae hatch, they’ll stick around to continue the cycle. You can also try thistle gall flies, but they can be difficult to purchase.

If you aren't interested in using toxic herbicides to get rid of the thistles in your yard, there are a few more natural options you can try. Vinegar is probably the only natural DIY option that will kill thistles. Pour white vinegar into a spray bottle. Then, spritz the vinegar directly onto the thistle plants until the plants are dripping with vinegar. It can take a few days or weeks, but the vinegar can eventually kill the thistles. You can also try using animals such as goats to gobble up the thistles. Some companies actually use goats to clear weeds from the land, and you can use them to take care of your thistle problem Look online to see if there are any companies that offer goat services in your area.