If You Use Salt To Kill Weeds, You May Be Making This Critical Mistake

Now that the harmful chemicals present in many commercial herbicides are well-known, more and more gardeners are turning to old-fashioned DIY ways to kill weeds. Luckily, there are many ingredients that you probably already have at home (like vinegar, lemon juice, and boiling water) that are great at getting rid of pesky unwanted plants. However, there is one common household ingredient that is often recommended as a weed killer that may turn out to be a big mistake: salt.


While salt does indeed kill plants, the problem with adding it to your yard is that it can have other unwanted consequences. In fact, adding salt water to a weed will not only kill the weed but may also kill other nearby plants and can even remain in the soil for years, preventing anything new from growing. Since you probably don't want a yard or garden filled with patches of barren earth, it's best to avoid using salt as an herbicide unless you are very sure you don't want anything to grow in that area. 

How salt kills plants and damages the soil

The reason salt is so effective at killing weeds is that it can block a plant from absorbing water. This happens because salt attracts water and can pull it directly from the roots of a plant through osmosis. This means that even if a weed gets enough water after you've added salt to it, it likely won't receive any of that water and will continue to wilt and eventually die from dehydration.


Furthermore, even if the plant doesn't die from dehydration, it will likely die from salt poisoning. According to Sciencing, this happens because if the plant does end up pulling salt into its roots, the mineral can start breaking down plant cell structures and prevent important chemical reactions necessary for survival, like photosynthesis.

While this is great news for weed killing, the problem is that if you add enough salt, it may even start taking water from nearby plants instead of just the weed you poured your DIY salt and water mixture over. 

How to safely use salt to kill weeds

All that being said, there are certain situations where using salt to kill weeds can be safe. First, if you want to kill weeds in an area where you don't want any plants to grow in the future, using a DIY salt and water herbicide can be a great option. Some examples where this would work well include cracks in the driveway or patio or underneath a layer of rocks on a gravel path.


However, when you do use salt as a weed killer, it is important to mix it with the right amount of water. Most websites recommend a three-to-one water-to-salt ratio as a good place to start. This is because if you add too much salt, you risk some of it running off into rivers and lakes or getting into the water table and causing environmental damage.

If you do decide to use salt as an herbicide in your garden, it is important to pour the salt water mixture very carefully into the roots of only the plant you would like to kill. This can be done by using a funnel to prevent splashing. Don't pour salt water onto the leaves of the plant because the water will simply run off and not cause much damage. While salt can damage a plant's leaves, it can only kill a plant from the roots.