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Does Epsom salt kill weeds? Everything to know

Epsom salt is a naturally occurring mineral salt and it has many applications. In medicine, it is useful for relieving pain and acts as a healing agent. Also known as magnesium sulfate, Epsom salt has long been used in agriculture and gardening for healthy plant growth.

This is why many gardeners have also recommended it as a useful agent for killing weeds.

Does Epsom salt kill weeds permanently?

Epsom salt kills weeds since it is toxic to plants and will damage their leaves and stems upon exposure. While this homemade herbicide harms weedy plants, it is not ideal for long-term use since it can affect the soil negatively.

Furthermore, it impedes the movement of water through the soil and degrades its structure. Epsom salt becomes useful if used moderately and as a pesticide to eliminate pests and bugs on your plants.

At the same time, Epsom salt contains magnesium and sulfur. These are two essential nutrients for specific plants. When you spread it on vegetation, it will act as fertilizer to help it grow. So, rather than killing weeds, it may spur their growth.

How does Epsom salt kill weeds?

Epsom salt is water-soluble. When used in your garden, the weeds will absorb the salt and disrupts the growth cycle. The absorption will dehydrate the plant and break up the internal water balance of the cells.

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epsom salt

Although the weeds will dry up at the top layer, the salt may not offer a better or long-term solution for large areas. You will need a lot of the compound, which can be risky since too much of it can harm the soil by increasing its saline content.

How long does it take for Epsom salt to kill weeds?

When you apply a solution of Epsom salt and water to weeds, do not expect to see the results immediately. It can take up to ten days for the compound to kill the plants.

But understand that if you are dealing with deeply rooted perennials, they will only die off after a couple of weeks and start growing again at the beginning of their season.

Does Epsom salt kill moss?


No scientific evidence is available to show that Epsom salt kills moss. But one thing to understand is that only specific types of salts are excellent remedies for moss.

The potassium salt is a great example of a salt that can kill moss without harming other vegetation.

What do you mix with Epsom salt to kill weeds?

You can combine Epsom salts with several other ingredients to kill weeds. Here are a few examples.

1. Epsom salt, dishwashing soap, and horticultural vinegar

For this recipe, you will need:

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  • Mix all the three ingredients in a bucket and stir them to combine well.
  • Pour small quantities into a spray bottle.
  • Allow the solution to settle for two minutes.
  • Spray it on weeds.

When spraying, ensure to soak the weeds with the solution for better results. Expect the plants to die after at least a week.

2. Epsom salt and warm water

Boiling water is an excellent substitute for vinegar Epsom salts and dish detergent as a weed killer. You will need:

  • Two cups Epsom salt
  • Two liters of boiling water


  • Mix the Epsom salt and boiling water in a large spray bottle.
  • Ensure you have mixed them well to form a solution.
  • Spray the solution on the weed from top to bottom

Ensure each plant soaks in plenty of the solution from the leaves into the roots for better results.

3. Epsom salt, horticultural vinegar, and essential oils

The essential oil you will use works by coating the plants and inhibiting respiration. You will need:


  • Mix all the ingredients in a sprayer
  • Spray the solution on the weeds

Whenever you mix all the necessary Epsom salt weed killer ingredients, ensure to spray the solution in the afternoon when the weeds are not wet from dew.

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Last words

Although Epsom salt can be useful in killing weeds, it may not be the best herbicide to use long-term. For small gardens or pavements, you can use a combination of Epsom salt, horticultural vinegar, and dishwashing soap as a solution for killing weeds. Alternatively, use Epsom salt and boiling water to control weeds.