At a high enough concentration, salt is toxic to all plant life. So killing horsetail with salt definitely works.
But there’s a big drawback:
You have to be very careful where you use it. Why?
Because it makes the soil unfit for replanting. And it can linger for a long time.
If you’re still interested in giving it a try, I’ll show you how it works, how you can use it, and the problems you’ll need to avoid.
Let’s dive in.
How Does Salt Kill Weeds?
Salt harms plants by the process of osmosis. Salt causes water to be drawn out of the plant cells from an area of low salt concentration towards a higher concentration. When you spray the plant leaves with a salt solution this dries out the plant. Killing the areas it touches. So salt acts as a contact weed killer.
But even if you kill the foliage, some weeds will regrow from their roots. So you also need to pour the salt solution onto the soil around the base of the plant. This increases the salinity of the soil around the roots. Causing water to be drawn out of the roots by osmosis, killing them and killing the plant in the process,
Salt is highly effective as a weed killer. If the soil becomes saline enough, most weeds will struggle to survive.
Killing Horsetail With Salt
As indestructible as horsetail sometimes seems, even this prehistoric survivor can’t live in heavily saline soil. If you pour enough salt solution into the ground then horsetail weed will eventually die.
The process is simple:
1. Mix water and salt in a 3:1 ratio. Then soak the soil around the horsetail plants.
2. If you use boiling water then you can soak the plant as well. This dissolves the waxy coating on the horsetail and exposes it to the salt. Improving your chances of killing the plant on contact.
3. If you don’t see results after a few applications you can increase the concentration of salt in the solution.
4. You can also try adding soap and vinegar, which many people recommend to improve the results.
But unfortunately, there are drawbacks to using this method. So I don’t usually recommend it.
Why I Don’t Recommend Using Salt To Kill Weeds
The big problem with using salt in your garden is that it makes the soil inhospitable to all plants, not just the horsetail. And it can stay in the soil for a long time, preventing you from replanting in the area.
Another problem is that it won’t just stay where you pour it. Over time it leaches sideways through the soil into adjacent parts of your garden. Killing grass and desirable plants. So it’s very difficult to control.
If you do decide to use it, then stick to areas where you don’t want anything growing again. Such as between patio pavers or to kill horsetail that’s growing through concrete. But salt can also damage paving stones, so you have to be careful when doing this.
Instead of using salt, there are better and less destructive methods you can try.
What Else Can You Do To Kill Horsetail?
Despite horsetail’s reputation for being difficult to kill, you can buy herbicides that can help you get rid of it. It often takes more than one application, but using a good horsetail weed killer that can kill the plant to the roots can prevent it from sprouting new shoots.
Using a weed torch to kill horsetail with fire is another effective approach if you’re willing to work at the problem over multiple seasons.
You can find more information about popular ways to kill horsetail here: