Will Soft Water Kill Grass? Everything You Need to Know

There are neighbourhoods that get a supply of “hard” water in their areas. Hard water gets its name because it contains an excess amount of dissolved magnesium and calcium. Although it isn’t a health risk, it is a nuisance due to the mineral buildup on plumbing fixtures. It also leads to poor detergent and soap performance, making it difficult for us to stay clean. As a result, we are left with water that’s uncleaned and bad in taste.

That is why water softeners are used to alleviate this problem. Water softeners treat hard water with potassium and sodium, which removes the mineral buildup in our water supply, turning it soft in the process. After this, we can clean ourselves properly, maintain cleaner appliances, and also appreciate its taste. But while these benefits are all good for us inside the house, will soft water kill grass and plants that are outside our house? We’re about to find our answers here in this article.

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Is Soft Water Good or Bad for Plants and Grass?

Most plants are unable to tolerate high levels of salt or sodium. And since most water softener systems produce a high amount of sodium, it is unwise to water plants with softened water. The reason why this is so is that excess sodium can interfere with the plants’ water balance and can trick them into thinking that they have acquired more water than they have, which therefore leads to dehydration in the soil.

Of course, if you’re only starting to use softened water on grass and plants, the effects won’t show right away, not unless you use them on a consistent basis. If this keeps up in the long run without you knowing the effects of excess sodium, your plants could eventually die. And this is a serious concern considering grasses are usually the most tolerant of salt and can handle large concentrations of up to 2300 mg for every kilogram of leaves.

Besides this, excess sodium poses another risk by causing dehydration in the soil quantity. What’s worse, is that it also creates a hazardous planting environment for more plants in the future since the soil will prevent proper water absorption.


As we said earlier, most plants are intolerable of salt, but not all of them. Some of these few exceptions include ferns, maple trees, and oak trees. It’s like we said earlier, grass is usually more tolerant of salt than plants. With all that said, we believe we finally got the answer to the question of “is softened water bad for grass?” But now that you have learned this, here are a couple of alternatives and solutions that you can use to set things right for your plants and grass:

Soften Water Solutions/Alternatives

It doesn’t matter whether you have a water softener installed in your household or not, there are other ways where you can give your garden or lawn the proper refreshment that it needs. Some of these alternatives include:

1) Install a Bypass Valve

Before water comes out of the water softener, it needs to get in first. Since you’re trying to avoid softened water, you’ll have to install a bypass valve. By linking this valve to an outside tap or outlet, it bypasses the softening treatment, allowing you to water your plants or grass without any excess sodium in the supply. As such, your plants and grass will avoid dehydration and eminent death. The only thing that we must warn you about is that you shouldn’t drink water from this outlet.

2) Salt-Free Water Softeners

You can also use a water softener that doesn’t use salt to get rid of the mineral buildup in your water supply. To learn more about salt-free water softener systems, head to American Home Water and Air.

3) Use Rainwater

Whenever possible, you should collect as well as water your plants using rainwater. This is because rainwater is clean and is considered “naturally soft water” as it doesn’t have a considerable amount of dissolved minerals. You can use a plastic garbage can or even a barrel to collect rainwater at the bottom of the downspout.

4) Mix Softened Water

You can also use rainwater from the previous point and mix it with large amounts of distilled water so that the combined solution dilutes softened water. This process will reduce the sodium content from softened water that will be more beneficial to your plants and grass. But it’s important to keep in mind that the salt levels in your soil may still build up. That’s why it’s crucial for you to test whether your soil is still healthy and fertile.

5) Dechlorinate Tapwater

If you’re using tap water to water your plants or grass, you have to ensure that it isn’t high in chlorine as some plants are intolerable of it. This can be determined by the strong chlorine odour or taste. So we suggest that you allow the tap water in your watering can to sit for a couple of days for it to dechlorinate.

Treating Plants That You’ve Already Watered With Soft Water

If you are unaware of the effects of softened water before and have already watered your plants with it, don’t worry as all hope isn’t lost. There is a way for you to fix it.

If you see that your plants are becoming dehydrated due to the excess sodium from softened water, then just stop using this type of water and just use regular water or, as we said earlier, rainwater. This will enable your plants and grass to get the right type of water that will help them grow healthily. However, It may take time for your plants to recuperate from the damage that they took from softened water. So it’s best to be patient in times like this. There’s even a good chance that your soil may have bared the brunt of softened water as the buildup of sodium results in soil imbalance. Unfortunately, there aren’t any chemicals that can reduce the salt content in your soil.

However, you can reverse the effects with a process known as leaching. It is when you water the soil using regular untreated water or rainwater in order to ‘flush out’ the sodium content in your soil.But you must also ensure that there is sufficient drainage to get rid of excess water, or else the grass and your plants will become waterlogged. Eventually, your plants and soil will return to their previous healthy state, provided you consistently monitor the soil levels until the proper results have been achieved.