How to use Water Softener Salt to kill weeds

As a gardener, you’re probably familiar with pesky weeds and their resilience to popping up all throughout your beautiful garden or yard.

Even though this is just a part of the joys of gardening, you’re not alone in wishing that you could find a way to get rid of the weeds once and for all. 

While there may not be a magic cure-all, there are many options out there for helping diminish any weeds that have started popping up, one of them being water softener salt.

If you’re curious about using this method of killing weeds, this article will go over everything you need to know.

Will Water Softener Salt Kill All Plants?

Unfortunately, yes, water softener salt isn’t selective on which plants it gets rid of, meaning it could also kill off the plants you want to keep. For this reason, it’s best to use salt in areas that aren’t right beside wanted plants, as there is no way to effectively ensure the saltwater runoff won’t find its way to their root systems too. 

In secluded patches of weeds or along the cracks of your driveway, this method is a great option, although for spot-treating throughout your garden—maybe not so much.

You don’t want to risk killing your desired plants just to get rid of a few weeds, so be sure to use the water softener salt method with caution. 

How Exactly To Use Water Softener Salt to Kill Weeds

This method of abolishing weeds is not only effective but also fairly simple. Salt works as a weed killer by sucking the water out of the plant, which they, of course, need to survive. 

Using water softener salt will not only kill the weeds, but it’ll also keep them from popping back up in that area for a couple of months to a couple of years.

There are a couple of ways to go about using this method, so we’ll go over them both so that you can decide which one works best for you.

Method to Use if You Don’t Have Kids or Pets Playing in the Area

Step 1: Sprinkle the water softener salt at the base of the weeds you’re looking to kill. You’ll want to adjust the amount you use to the size of the patch of weeds, so keep that in mind when purchasing and sprinkling the salt. For example, a 1/4 cup of salt will kill a smaller patch of weeds, but you’ll want to use more if you’re killing a larger area.

We recommend using this water softener salt below.

Morton salt 1499 clean protect, 25 lbs,Pellet
  • Helps clean your water softener while it works to remove hard water minerals
  • Helps prevent mineral buildup in pipes and appliances
  • Helps improve efficiency and extend the life of appliances of water heaters

Step 2: Combine one cup of the salt with one gallon of boiling water, making sure the salt gets properly dissolved. While it’s still hot, pour the hot water mixture directly onto the weeds.

Step 3: Combine half a cup of the salt with one quart of white vinegar, then mix until it’s completely dissolved. After that, pour the mixture into a spray bottle and then spray it onto the weeds. 

With three short steps, this method is quick and simple, although if you have any particularity stubborn weeds, you can always repeat this process a few days after the first application. 

This method is the most effective, as the sprinkled salt will continue to dissolve as the days go by, although if you have any pets or kids that may ingest the salt, it’s best to use method two.

Method to Use if You Do Have Kids or Pets Playing in the Area

Step 1: Heat two cups of water and add one cup of water softener salt, stirring until it’s dissolved. Since you won’t be sprinkling any whole salt chunks around the weeds, the salt ratio in this method is higher.

Step 2: Pour hot saltwater mixture onto weeds, repeating every few days if necessary to completely kill off weeds.

Step 3: Combine salt and white vinegar until dissolved, then pour into a spray bottle. Mist the weeds generously, repeating every few days as needed. This step is somewhat optional in this method, as the repeated hot saltwater mixture may be enough on its own.

Although the two methods of using water softener salt as a weed killer are quite similar, the second one doesn’t require any whole pieces of the salt to be in your yard or garden, which is important if you have kids or pets that may try and consume it. 

Once deciding which method is best for you, getting the supplies and carrying out the process of applying it to the weeds is fairly simple.

Will Water Softener Salt Kill Weeds?

Yes, water softener salt is effective at killing weeds when applied correctly. Not only will it kill them, but it’ll also stop them from growing back for up to a few years. Monitor the weeds to see how many times—if at all—you’ll have to repeat the process to kill them successfully. 

If you do have to do the process a few times, don’t fret—the weeds will all eventually die.

Some of the more resilient weeds with more extensive root systems may just need to have the saltwater softener applied a few times over.

How Long Does It Take For Water Softener Salt to Kill Weeds?

This timeline can vary depending on the size of the weed and the weather conditions, but it usually takes around ten days for the unwanted plant to die fully. 

Since this weed-killing method works by disrupting the plant’s growth cycle and pulling all the water out of it, it does take quite a few days to work completely.

Even though the weeds’ demise may be slow, the saltwater softener will still prove to be effective at getting rid of them.

Certain weeds with stronger root systems may be more resilient, so if this is the case, you may have to reapply the salt in order to fully kill them off. Plants—or as it seems, weeds in particular—will try their absolute hardest to continue to thrive even in conditions where the odds are stacked against them, so sometimes it takes a bit of extra effort to kill off those pesky weeds once and for all.


Many people use water softener salt as their weed-killer of choice, priding it on its effectiveness and simplicity. While fancy chemical killers do get the job done, salt is less harmful while still killing off even the most stubborn of weeds. 

Not only that, but the method of application is fairly simple and quick, leaving you with more time to tend to the things around your yard and garden that you actually take pride in. 

It’s important to remember that water softener salt isn’t selective at killing only weeds and avoiding your wanted plants, so use this method carefully and always be sure to plan ahead—you don’t want to accidentally get rid of one of your favorite plants. 

When prepared and used correctly, water softener salt is an excellent and inexpensive weed killer, working by drawing all of the water out of the plant.

Next time you’re at the store deciding on which herbicide to purchase, consider water softener salt as a simple and easy way to get the job done.

Also read

How To Sterilize Soil So Nothing Will Grow

Will Bermuda Grass take over Weeds

How to Stop Weeds from Growing Through Pebbles

How To Keep Weeds Out Of A Playground

Leave a Comment