Chemical herbicides have their own demerits that include poisoning the soil and microorganisms. But did you know you can use salt for killing weeds organically? I’ve explained below how it works, how long it takes and some pictures after using it to get rid of weeds in driveways and patios.
Applying too much salt on weeds will kill them due to sodium chloride toxicity. You can apply rock salt or a highly concentrated salt solution on directly on the weeds to get rid of them in about 10 days. This homemade treatment can control weeds and vegetation permanently on the area it is applied.
Does rock salt kill weeds permanently?
Salt works by dehydrating plants and disrupting the water balance of plant cells. As the weed loses water, it starts to wilt and die off permanently. This organic weed killer prevents new weeds from growing where it is applied. You can use rock salt or even table salt to get rid of weeds.
Rock salt and table salt are both sodium chloride with different purification qualities. When applied in large quantities on areas with weeds, rock salt increases salt toxicity, killing weeds permanently.
If you want to use salt to kill weeds permanently, it is best to apply it in the following areas:
- Driveways (such as gravel driveways)
- Between pavers
- On walkway bricks
- On rocky areas in the garden
- Between rock crevices
The problem with using rock salt (the cheaper option) is that it will kill just about any plant in the area it is planted.
How to Use Salt to Kill Weeds
Both crystals of salt and a concentrated salt solution are effective at killing weeds permanently. You can choose to use a different recipe that may include ingredients such as vinegar and dawn dish soap especially if you’re opting for a liquid application.
Here’s how to salt the earth to kill weeds so that nothing grows:
Liquid salt solution application
- Add salt to water in a ratio of 3:1.
- Stir well to mix the solution not to leave any undissolved crystals.
- Spot spray the weeds in your yard, on paveways and driveways.
- Repeat this treatment after 7 to 10 days.
For this recipe, you can add a dish soap and white vinegar to make the homemade weed killer more potent and fast acting. Dish soap will act as a surfactant, making the salt solution stick on the plant.
Vinegar is a highly effective organic herbicide. When coupled with salt, it makes a highly potent weed killer. The solution can control weeds permanently when applied.
Salt solution is best used on hard surfaces and not places with bare soil.
Solid rock salt application
If you don’t want to spray the salt solution on weeds, you can apply it as a solid form. To kill weeds using rock salt, sprinkle generous chunks of rock salt on the soil surface where there are weeds. Apply it at the bases of weeds too.
This way, the salt will gradually leach into the ground and prevent anything from germinating for years to come. This makes it a great for killing grassy weeds that keep growing in driveways and pavements.
How long does it take for salt to kill weeds
It will take at least 10 days for salt to kill weeds completely. This duration may vary depending on factors such as rain conditions, the concentration of the salt solution you sprayed, and the size of the weeds you’re trying to get rid of. 2 to 3 salt applications may be required to kill weeds permanently.
Note that the higher the concentration, the faster you’re likely to control weeds with salt for the longest time. For example, rock salt, when applied in plenty, can remain in the soil for years, preventing plants and weeds from growing permanently.
Disadvantages of using salt homemade weed killer
As you’ve seen, salt works well as a water soluble weed killer. It is effective and can knock out weeds in rocky gardens, paveways, patios and even in gardens.
However, you may want to be aware of the following disadvantages of using salt organic weed killer:
- Salt is a non-selective weed killer. This means it will kill all plants that you’ll apply it on. If you use it in your lawn, it will kill even the desired grasses. If you want to prevent this, ensure you spot-treat the weed with the concentrated salt solution.
- You’ll need large amounts of salt to eliminate weeds permanently. Since high concentrations of salt solution will get the best results, you’ll definitely use a lot of salt crystals to get the job done. Several treatments may also be needed for killing weeds with salt to work.
- Salt is not effective for killing perennial weeds with underground rhizomes. Weeds such as quackgrass can remain in the soil and sprout later in the season even after treating with salt herbicide recipe.
Of all those disadvantages and precautions of using salt to control weeds in gardens, yards and patios, I concluded that you have to choose the right places to kill weeds with salt.
Driveways, spaces between patio cement, rocky areas in the yard, and places where you don’t intend to grow anything any soon are the best for treating with salt as a herbicide.
If you intend to kill weeds in your lawn without killing grass, salt is not the best option unless you spot-treat the weeds. The problem is that you may find it hard to overseed or reseed the bare spots because of the high concentrations of salt in the soil.
- North Dakota State University: Homemade Herbicide with Salt
- University of Massachusetts Amherst: The Impact of Salts on Plants and How to Reduce Plant Injury from Winter Salt Applications
- University of Illinois at Urbana – Champaign: Q & A: Killing weeds with salt
My name is Alex K. Worley. I am a web geek who loves gardening and connecting with nature. I maintain a small backyard organic garden from which I source most of my green food. I hope to help you learn something new about gardening.