By Mark Nelson — President, Nelson Water

With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.

Whether you’re a keen amateur gardener or have a serious green thumb, you’re likely to appreciate the importance of water on your plants. What you may not have considered is whether the type of water you’re using is having an impact on your garden. So, here we will explore the differences between hard, soft and reverse osmosis water to help you determine the best choice for everything in your garden.

Is Hard Water Hard on Plants?

The term “hard water” is used to explain the presence of calcium and magnesium minerals. Around your home, these mineral deposits can cause a buildup on plumbing fixtures, stains, and spotting. So, it would be easy to assume that hard water must be bad for plants. In fact, these hard water minerals can actually be beneficial to plant life. You’ll need to check for signs of stunted growth that may be caused by very high levels of hard water minerals.

If you grow acid loving types of plants such as Begonias or Azaleas, you will need to check your water pH. It is common for hard water to have high alkalinity, so this could cause plant growth problems. In this scenario, you may need to switch to reverse osmosis water.

Soft Water and Plants

If your plants are exposed to lots of rainwater, an occasional watering with soft water is not likely to cause any harm. Unfortunately, if you’re watering your plants with only soft water, your garden is likely to suffer. Most types of water softener need sodium chloride for ion exchange. This can lead to a gradual sodium build up in your soil, creating plant growth issues.

Instead of using soft water, it is better to use reverse osmosis or hard water for your plants. Fortunately, it is possible to create a bypass from your water softener. This means that you can have the water for outdoor taps and spigots bypassing softening treatment, so you’ll only have soft water where you need and want it.

Using Reverse Osmosis Water

Reverse Osmosis systems are very effective at reducing contaminants, making them a popular choice for keen gardeners. The greatest benefit of an RO filter is that your garden can enjoy consistent, clean water. This allows you to easily control your nutrient and fertilizer levels by adding what you need for your specific plants. If you have iron, chlorine and bacteria water issues, your garden is sure to appreciate the switch to reverse osmosis water. It’s simply like having pure rainwater out of your taps. Additionally, it is easy to change the pH of RO water. So, if you have plants with specific alkaline or acid requirements, you can benefit from the versatility offered by reverse osmosis.

While it’s fine to use hard water for your garden, if you have delicate or diverse plant life, it can create problems, particularly if the only source of water is hard water. If you’re concerned about whether your water is suitable for your garden, look out for damage caused by high levels of minerals or alkaline pH.

Serious gardeners will find that reverse osmosis provides the best option, allowing precise control of nutrients for your plants, so it may be worth speaking to a water treatment specialist for further help.