Can soft water hurt when watering my yard?

I recently purchased my water softener from and I understand that after the water softening process there are more of some things and less of others…

Can watering my lawn with soft water be damaging to my grass and flowers?

Answer:  (We’ll edit our answer, as our reply seems to be misinterpreted)

 Softened water is not damaging to grass or plants.  The reason for the concern is somewhat anecdotal, but not based on any real science.  Plants require water to develop and thrive, however, owners of water softeners were concerned that the small amount of added salt, and low levels of magnesium & calcium in the water may inhibit plant growth. In reality, there are only very low levels of salt added to softened water (about 7 mg/l per grain of hardness), and this extremely low level is not a factor in plant development.  For a real life comparison…

( here’s the edit – our comment was meant as an EXTREME comparison only for demonstrative purposes – the comment describes a residence not located directly on the beach, but rather “near a beach”.  In a casual manner, we had tried to infer that the level of salt exposure blocks away from the shore on non-salt acclimated plant life was higher than would be found in softened water, but still does not detrimentally effect growth.  This comment was not meant to infer that any non-salt adapted plant would survive directly in a beach environment – as it would not – but rather that a lawn blocks away from the coast would not be damaged due to slightly elevated sodium content in water. This also does not infer from a technical stance that locating a non-salt adapted plant life near a beach is preferred, only that general gardening using softened water with slightly elevated levels of sodium does not show a significantly negative effect.  It should also be noted that different plants have varied tolerance levels to sodium, but these different tolerances are more important when measuring crop production, and not general household gardening.  There are many references in the literature that describe these effects, but a common reference easily found on the internet would be the paper  “Water Quality For Agriculture”, R.S Ayers (Univ. of CA, Davis) , D.W. Westcot (SWRCB), 1976….degreed marine biologist and chemical engineer)

….consider plant growth at any residence located near a beach – sea spray is extremely high in sodium concentration, and in this case plants would have a significantly higher exposure to salt – but there is no ill effect.  The other consideration is the low level of magnesium and calcium in softened water.  Plants requiring these nutrients obtain the majority of what they need from the soil, and not irrigation water.  In addition, professional hydroponic growers frequently use water prepared by the process of reverse osmosis – this process removes a much higher level of the contaminants then a water softener would – and plants still thrive.

The other option is (as one of our posters mentions in the comment below) to by-pass the irrigation system or outside hose bib so that it is not supplied with softened water.  However, the main reason for doing this is to conserve salt.  Since plants do not care one way or the other whether the water is softened, it is not necessary to waste salt by softening the large volume of water used for lawn and garden watering – better to by-pass.


  1. I have always heard that soft water is not ideal for your lawn nor plants… However, make sure the water softener system actually does service the outside faucet lines. If not you should be good to go! If so, start collecting rain drops for future use!

  2. Another option is that you can always use non-sodium potassium chloride rather than sodium chloride – the potassium in the water is a fertilizer and nutrient – good for plants. The downside is that with increased use of potassium for agricultural purposes (for instance in growing bio-fuels), the price of this material is significantly higher when compared to sodium chloride. Whatever you decide to use, we always recommend that you use sodium chloride or potassium chloride purified for use in water softeners (available at many supermarkets, plumbing supply and hardware stores). Non-sodium potassium chloride is commonly available and sold under the brand names Morton KCL, K-Life, Softouch and Nature’s Own.

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