Softened Water And Plants: Using Softened Water For Watering
By: Heather Rhoades
There are some areas that have hard water, which has a high amount of minerals in it. Softened water tastes better and is easier to deal with in the house, but what about with your plants in your garden. Is it okay to water plants with softened water?
What is Softened Water?
Softened water is water that has been treated, normally with sodium or potassium, to help remove minerals from hard water.
Can You Use Softened Water on Plants?
Most of the time it is not a good idea to water your garden with softened water. The reason for this is that softened water typically has a high amount of sodium, which is attained from salt. Most plants cannot tolerate high amounts of salt. The sodium in softened water actually interferes with the water balance in the plants and can kill plants by “fooling” them into thinking they have taken up more water than they have. Softened water essentially causes the plants in your garden to die of thirst.
Not only does the salt in softened water hurt the plants you water with it, the salt in the water will build up in your soil and will make it difficult for future plants to grow.
Soft Water Homes and Watering
This is not to say that if you have softened water you cannot water your garden and lawn. You have a few options if you have softened water.
First, you can have a bypass spigot installed. This means that you can have a special spigot installed on the exterior of your house that takes water from the water line before the water is treated in the water softener.
Second, you can try mixing your softened water with collected rainwater or distilled water. This dilutes the effects of the salt in your softened water and makes it less harmful to your plants. But be aware that the salt in softened water will still build up in the soil. It will be very important that you regularly test the soil for salt levels.
How to Treat Soil Affected by Softened Water
If you have soil that has been watered too much with softened water, you will need to work to correct the salt levels in the soil. There are no chemical ways to reduce the amount of salt in your soil, but you can do this manually by frequently watering the affected soil. This is called leaching.
Leaching will draw the salt out of the soil and will either push it deeper in the soil or will wash it away. While leaching will help to draw the salt out of the affected soil, it will also draw out nutrients and minerals that plants need to grow. This means that you need to make sure to add these nutrients and minerals back into the soil.
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Read more about Environmental Problems
Hard water contains calcium and magnesium carbonate salts. At home, it causes stains, spots, and build up on your sinks and fixtures. But in the right amount, hard water minerals can be good for your plants. Just be sure to check for any signs of stunted growth since very high levels of calcium and magnesium can hurt more diverse gardens.
If you’re growing acid-loving plants like Azaleas, Caladiums, and Begonias, you’ll need to check the pH of your water. High alkalinity is common in hard water and may cause problems for plant growth. In this case, reverse osmosis water can offer more controllable watering.
What Are the Effects of Soft Water on Plants?
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Soft water, in the most basic form, is water that has had salt added to it. There are some benefits of softened water, but using soft water on plants can be harmful to them. If used to water plants, soft water can make it hard for the plants to grow and limit the availability of nutrients. It can also leave salt deposits in the soil that can build up and prevent anything from growing. There are a few reasons to use soft water in the home, however, including the prevention of pipe blockages from mineral buildup.
Buildup of calcium in showers may also be prevented with softened water. The treated water does not remove harmful substances such as lead. It can therefore cause other problems if used for cooking or drinking, and should not be used with plants either. The salt, or sodium chloride, prevents water from being absorbed by a plant. Using soft water on plants at home or in the garden can dehydrate them not enough water will be absorbed for sufficient growth, or the plants could die.
Calcium can be detrimental to plumbing systems, but is an essential nutrient for plants and gardens. Using soft water on plants can also wash away calcium and other substances that are beneficial. Usually, not enough nutrition is available if softened water is used for watering plants. The salt deposits can remain in the soil, and even spread when it rains. Whole gardens and the land around them can become unsuitable for growing plants at all.
For anyone who needs to use soft water on plants, it is important to test the nutrient level of the soil often. There are soil testers than can help monitor nutrient levels. Calcium and other nutrients will have to be added on a more regular basis as well. It also helps to dilute the soft water adding rain water or mineral-filled fluid can help replace the nutritional substances in the soil.
The acidity of soft water makes it suitable only for plants that grow where the soil is acidic. These include tomatoes, azaleas, roses, and blueberries. Otherwise, soft water on plants can be detrimental to their ability to thrive and could possibly kill the entire garden. Soft water is also not the best option for use in drinking water, infant formula, or cooking because it can contain dangerous heavy metals. It is, however, fine for use with laundry or in equipment such as steam irons and car batteries.
Using Soft Water For Lawn Care
Water softening is a godsend for homes with hard water. Hard water requires more soap and detergents to get things clean softening your water will make household chores a breeze. Soft water prevents ugly orange staining and clogged pipes. It makes water taste and look better, too. Shinier hair, cleaner tubs and appliances…soft water benefits us in a number of ways. On the flip side, lawns and gardens don’t always like it so much.
When it comes to the water on the outside of your home, there’s a chance that soft water could have a less than positive effect on the quality of your lawn and garden. If you’re using treated water on your outdoor greenery and it seems to have a difficult time thriving, it could be that your plants just don’t do well with soft water.
What Your Lawn Is Trying To Tell You
You’re doing everything right. You water in the morning when the sun isn’t likely to burn your plants and the soil won’t stay damp all day. You never overwater, to keep your flowers from wilting. You fertilize, weed, aerate, even send a few prayers out to the lawn gods. But something else is making your garden unhappy, and the long-term use of treated water is beginning to appear suspect.
Why isn’t your softened water good for the lawn? Softened water is treated with salt to help remove the minerals from hard water. The resulting soft water contains excess sodium, which can fool plants into thinking that they’ve absorbed more water than they have, causing dehydration.
Soil quality is also affected in areas where rainfall is scarce because watering with soft water causes salt buildup on the surface. Areas that receive regular rain are not as sensitive to sodium accumulation because natural rain washes salt away. It’s unlikely that your water softener salt will kill your grass, especially not by using it to water occasionally. But prolonged use of soft water just isn’t ideal for your garden.
Soft Water In, Hard Water Out
You have a whole home water softener but you don’t want to use soft water for your garden. What should you do? One option is to go green and collect water in a rain barrel. It’s a great way to conserve resources, and rainwater is fantastic for your garden. Rain is “naturally” softened water as it hasn’t had time to collect many dissolved minerals from the ground. Plants love rainwater, and it has the perfect pH balance and nutrients to keep soil and plants healthy.
Using distilled water is also good for use in gardens, but the expense of using distilled water for a larger area can be too much for most homeowners. Distilled water contains no minerals, making the need for fertilizers essential to keep a healthy garden.
Perhaps the easiest route for watering your outdoor area with unsoftened water is to use the bypass valve on your water softener. This can be used to temporarily bypass the softening system to access untreated water. If you link this bypass valve to an outside tap or other outlet, you can use the untreated water to water your garden with a hose, as you would do normally.
A separate spigot for outdoor water with a water line independent of your water softener allows you to draw water from the water line before it’s treated so that you can water your lawn and garden without softened water, but you’ll still reap all the benefits of soft water inside your home.
Green With Envy
There are always those lawns in the neighborhood that seem to fare better than everyone else’s. They stay green in times of drought, dandelions don’t dare encroach, and its carpet-like appearance begs you to lie down and nap on it. Most likely those lawns have been tended to as carefully as a shepherd guards his sheep.
It’s true that lush, green lawns make a statement. A properly maintained yard makes us look and feel good about ourselves-- it may even reveal your status in the community. Anyone who has spent countless hours cultivating finicky vegetation knows achieving the perfect, emerald green lawn takes more than regular mowing, and the slightest changes in weather or water can transform soft, thick turf into a patchy, prickly jungle nearly overnight.
Giving your landscape what it needs means troubleshooting problems as they arise, and dedicating a fair amount of effort to the task. Pay attention to your soil and water quality, and look to your plants for clues it’s getting the proper nutrients. Using untreated water for your lawn and garden is the safest bet for keeping it in tiptop condition.
Enjoy your good, soft water for bathing, drinking, and household chores water softeners do excellent work inside your home. But when it comes to keeping your grass green, and your neighbors green with envy, using rainwater or water that hasn’t been softened will give you the very best results.
So, What If You Have Softened Water Only?
Having softened water as your only option for watering your plants should not limit your passion for gardening. There are many available options you can undertake.
Install a Bypass Spigot
First, install a bypass spigot. A bypass spigot allows the water coming into your home to “bypass” the softener. You can have this device connected to channel water away from the water line before the softening process begins.
Mix Softened Water with Other Waters
You can also mix the softened water with distilled water or rainwater. This process dilutes the consequences of salt water in softened water and makes it friendlier on the soil and plants.
However, after some time the salt level in the soil is likely to increase. Thus, it’s advisable that you test the soil often to ascertain that it’s still healthy. You can also check out Distilled water vs. purified water to make a more informed decision.
Morpheuspa (6B/7A, E. PA)
I see that most water softener salt is, simply, sodium chloride. Some is potassium chloride. Some are other salts. We'll assume yours will indeed be sodium chloride. It's cheap and effective.
ETA: 103 mg/L easily translates to 103 PPM. Which is a fair clip, actually. /ETA
If rarely irrigated and flushed through by ample rainwater, practically nothing is the result. So if, like me, you're in the habit of irrigating once or twice a year, absolute maximum, then don't worry about it. Even sodium-sensitive plants won't notice that.
If you happen to live in a semi-arid or arid area and irrigate all the time, irrigate in smaller amounts that never wash the sodium below the root zone, and never receive ample enough rainfall to leach the sodium out of the soil, you'll eventually end up with a dead, sodic soil that won't grow much except sodium-tolerant marsh grasses. And then, not even those. But maybe you can manage a few things that tolerate areas like the Dead Sea.
From the description, "not regularly" means your impact is towards the former. I'd be less inclined to worry about it, but would make sure to apply more water less often during dry summers to avoid sodium buildup.
Pro tip: Turn off your water softener when you're irrigating the lawn and simply let the hard water hit the lawn. The lawn really doesn't care about that and would much rather have the calcium than sodium anyway. Also, it's far cheaper in terms of your water softener salt. You can certainly turn on the softener temporarily if you need to use the water yourself, but why pay to soften hundreds of gallons that hits the lawn and doesn't do any good?
Lawn Watering - Using Soft Water for Irrigation
What do I need to add to my lawn when watering with soft water and how often?
We'll start by answering a couple of commonly asked question: What is soft water and hard water? Is it OK to water plants with softened water?
Hard water is water that is high in dissolved minerals -- specifically calcium (Ca 2+ ) and magnesium (Mg 2+ ) and sometimes iron (Fe) and manganese (Mn). Hard water reduces the effectiveness of soaps and detergents. It also leaves scale-like deposits on plumbing fixtures, stains and rings in tubs, sinks and toilets. The mineral buildup reduces the life of water heaters and home appliances.
One solution when dealing with the problems caused by hard water is to soften it. Water softeners use salt (sodium chloride or potassium chloride) to replace the scale-building minerals with sodium or potassium ions. Note: rain water is also considered naturally "soft" because it does not contain dissolved minerals.
Softened water is therefore high in sodium and is not the best water to use for irrigating lawns and gardens because it can cause salt buildup on the soil surface.
Watering with soft water is risky in areas that get little rainfall. In arid climates, irrigation water will evaporate quickly leaving
salt deposits. Natural rain tends to wash salts from the soil so using soft water is less of an issue in areas that get a lot of rainfall.
Avoid using soft water for irrigation on sites that have sodic ("salty" clay) soils. Sodic soils are common in the Southwest.
To answer your question: The University of Arizona recommends applying gypsum at a rate of 25 lbs per 1000 ft 2 twice a year (Turf Tips, February 2001) to lawns that are irrigated with soft water.
The gypsum will encourage sodium deposits to wash (or leach) out of the soil. I recommend core aerating along with the gypsum application to encourage water infiltration into the soil.
Another way to avoid salt buildup is to water heavily. Heavy watering will leach any deposited salts out of the soil while light watering will leave salt deposits.
Potassium chloride can be used in your water softener instead of sodium chloride. Potassium is a plant nutrient and it will not harm plants or soils. The down side to using potassium chloride is that it's a lot more expensive.
Have you considered by-passing the water softener for irrigation? If this is a possible option, it is my opinion that it is best to avoid watering lawns and landscape plants with soft water.