How Long Does It Take For Salt To Kill Weeds?

Did you know that salt can be used (cautiously) to kill weeds? Sometimes we need an alternative to chemical sprays and an opportunity to use something relatively inexpensive. Some of the most popular homemade weed-killer recipes include vinegar, dish soap, salt, or Epsom salts.

Advantages Of Using Salt

Salt is an excellent weed killer for small scale weed control. The availability of salt and its ease of use are obvious advantages. In addition, using salt is super cheap and readily available. A salt solution used in place of other herbicides helps to preserve the environment.  

How To Use Salt

Using water with salt can increase its effectiveness. Certain weeds will react to straight salt, while others seem to need water before the desired results are achieved. Be aware that it may take up to 10 days to see the salt’s effectiveness on the weeds. The weather conditions and the size of the unwanted plant will affect how well the salt works as a weed killer. The process involves disrupting the growth cycle. When applied to the weed, it is quickly absorbed. This makes the plant retain more water, causing it to wilt and die. 

Salt Recipes

Making a salt weed killer mixture at home is not difficult. You can add rock salt or table salt to hot water until it dissolves. Make a fairly weak mixture to start with. You can quickly increase the amount of salt daily until the salt begins to kill the offending weeds. It is also possible to use a combination of vinegar and salt to kill those pesky weeds. Mix 1 cup of table salt with 4 cups of white vinegar and ½ teaspoon of dish soap (one without bleach, fragrance, or degreaser is best). The dish soap’s use helps the liquid stick to the plant instead of simply running off the weed. This then makes the uptake of the salt by the plant both quicker and more efficient.

It is best to transfer the liquid to a clean spray bottle and set it on stream instead of mist or spray. This provides you with more control over where the homemade weed killer lands. Wait until there is a calm day and hot temperatures and thoroughly coat the weed with the mixture. Repeat the process once a day around the hottest part of the day until the weeds brown, wilt, and die.

Side Effects

If you decide to use salt or a salt and vinegar combination to kill your weeds, you need to be aware of the consequences. While the salt and vinegar combination is desirable for stubborn weeds in gravel drives and paths as well as cracks and crevices in walkways, applying this combination on the soil will make sure that nothing grows in that spot again.  

Further Disadvantages

Unfortunately, salt as a weed-killer generally only kills off the top layer of weeds. Typically, results will last for about 3-4 weeks, and then it may be necessary to spot treat new weeds. Fortunately, regrowth will happen less and less. It would be best if you were particularly careful where you apply the solution as it is relatively non-selective and can kill off good plants that you want to keep.  

It would take an excessive amount of salt to kill a large expanse of weeds, and it is unlikely to work on large weeds. A salt solution as a weed killer is not recommended to be used on lawns. The salt may damage concrete and other paving materials if used over an extended period though this is more likely to occur when salt is used neat on paving to kill the weeds. There is a risk that a little bit of the salt solution will run off onto planted areas when it rains.