Chemical herbicides are known to poison soil microorganisms, making them undesirable for weed control. A great natural alternative is using salt to kill weeds organically. But, how does it control weeds, and what recipe is effective?
You can use salt as an organic weed killer in gardens and driveways. Once absorbed, salt causes sodium chloride toxicity in the plants, thus killing weeds permanently. Mix salt, water, vinegar, and dish soap in a ratio of 3:1:1:1 and apply the solution on weeds daily until they die.
CAUTION: Salt is a non-selective weed killer and should only be applied on the target plants as a spot treatment. Otherwise, it will kill any plant it comes into contact with.
Does rock salt kill weeds permanently?
Use salt to kill weeds between pavers, in driveways, and gravel permanently. Applying too much salt on weeds will kill them permanently due to sodium chloride toxicity. You can apply rock salt or a highly concentrated salt solution directly on the weeds to get rid of them in about 10 days.
Salt works by dehydrating the target plants and disrupting the water balance in their cells. As the weed loses water, it starts to wilt and die off completely.
The organic weed killer prevents new weeds from growing where it is applied, but you can apply a lot of water to get rid of excess salt in the soil before planting something else in the area you applied it.
But what types of weeds can salt kill?
Rock salt or table salt will kill broadleaf and grass weeds in lawns, patios, walkway bricks, between pavers and rock crevices, gravel driveways, and rocky areas in your yard. You can use it as an alternative to Roundup to target dandelion, crabgrass, henbit, and purslane.
Rock salt and table salt are both sodium chloride with different purification qualities. When applied in large quantities to areas with weeds, rock salt increases salt toxicity, killing weeds permanently.
How to use salt to kill weeds
You can use a concentrated salt solution or salt crystals to target weeds in your yard. However, I’ve found that liquid recipes are the best for destroying stubborn weeds to the root.
To increase the potency of salt as a weed killer, you can add ingredients such as vinegar and dawn dish soap to the recipes.
Here are recipes you can use to salt the earth and kill weeds so that nothing grows:
1. Rock salt recipe
- Add rock salt to water in a ratio of 3:1. A higher concentration will also do.
- Stir well to mix the solution not to leave any undissolved crystals.
- Spot spray the weeds in your yard, patio, and driveways.
- Repeat this treatment after 7 to 10 days until all the weeds die.
2. Salt + vinegar recipe
Vinegar is a potent organic weed killer. Using it together with salt increases its efficacy as a natural herbicide.
Here’s how to use the homemade salt and vinegar to kill weeds:
Add one cup of salt to a gallon of white vinegar. Add two tablespoons of dish soap and stir to mix well. Pour the weed-killer solution into a plastic garden spray bottle. Spot spray the weeds to kill them to the root and prevent their regrowth.
The dish soap acts as a surfactant that helps the homemade weed killer stick on the target plant’s foliage for action.
Read also: Does borax kill creeping charlie weeds?
3. 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 directly on the weeds, covering their bases
The salt will gradually leach into the ground and prevent anything from germinating for years to come. This makes it great for killing grassy weeds that keep growing in driveways and pavements.
How long does it take for salt to kill weeds?
It takes about 10 days for salt to kill weeds, but that depends on factors such as the concentration, rain, and type of weeds. Weeds that spread their roots deep into the soil may take several applications to kill to the root.
Does pool salt kill weeds?
Pool salt is a potent weed killer. Pour 10 pounds of pool salt into a 5-gallon bucket full of water. Stir well and let it soak overnight so it fully saturates the water. Spray weeds the next day the gravel driveway and wait for them to die in 7-10 days.
Disadvantages of using salt homemade 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.
- It takes large amounts of salt to eliminate weeds permanently. You may need to treat weeds up to 5 times for the best results.
- Salt is not very 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.
If you intend to kill weeds in your lawn without killing grass, salt is not the best option unless you spot-treat the weeds. You may also find it impossible to overseed or reseed the bare spots because of the high salt concentrations in the soil.
READ NEXT: Dicamba Herbicides for Creeping Charlie
- 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