Do you know what type of water is flowing through your house and hose spigot? If you don’t, it’s easy to figure out. Next time you take a shower, pay attention to how your skin feels afterward. Do you feel slippery, or do you feel squeaky? If you feel slippery, then you have soft water. If you feel squeaky, then you have hard water. Does hard or soft water make a difference to your garden plants? As part of a plant’s holy trinity – water, sun, soil – you need to know what kind of water you are using. If you have been having a tough time getting anything to grow in your garden and have checked your soil and sun, then the problem could be your water. But what is the difference between hard water and soft water?

Hard Water

No, hard water doesn’t mean it’s mixed with alcohol. Hard water is comprised of dissolved minerals – the majority of which are calcium (Ca), magnesium (Mg), and lime. Unless you have a water softening system, hard water (to varying degrees of hardness) is the standard type that flows through public and private systems. Once again, there is an easy way to tell if you have hard water. If over time, white/pink scum builds up on your household fixtures (sinks, bathtubs, toilets, etc.), then you have hard water. Those buildups are caused by the minerals slowly collecting. However, that does not mean hard water is bad for you or your garden.

Soft Water

Soft water is treated, or softened, with sodium which removes the minerals. That’s why your skin feels slippery after showering with soft water and why glassware looks cleaner after washing with it. The minerals that build up on your skin have been removed, so there’s nothing to wipe off. To remove the minerals, water is treated with sodium in a system usually set up somewhere within your residence. Soft water systems are often installed in areas where there is a high amount of minerals in the water that may affect the plumbing, or simply because some people prefer the taste and feel of soft water over hard water. It may not leave buildup or residue on your fixtures and skin, but that does not mean soft water is good for your garden.

Pros and Cons for Gardening

The simple answer: Treated soft water has little to offer your garden other than plant-killing sodium. Although only trace amounts of sodium are present in soft water, it can build up over time in the soil. After enough builds up, the sodium causes your plants to die of thirst. If you are worried this is the case now, you should leach your soil. This is done by watering thoroughly and frequently, which basically washes away the sodium buildup. However, you’ll also be washing away some nutrients and minerals that are vital to your garden’s nourishment. If you leach your soil, make sure you replace the mineral/nutrient content afterward with an additive or fertilizer.

Hard water provides your garden with useful mineral content and doesn’t have the excess sodium of treated soft water. Calcium and Magnesium are vital to a plant’s growth but can be harmful in large doses. Too much can cause chlorosis – a yellowing of the leaves which is a symptom of sickness. To prevent sickness like chlorosis, use a raised garden bed that provides better drainage. Excess minerals will leach from the soil naturally, be rebalanced with the minerals in your hard water, and your garden will be much happier.

Which Should I Use for My Garden?

This is a trick question because the best option for your garden isn’t hard water or soft water, but rainwater. Rainwater, while technically soft water, lacks the sodium of treated water and won’t lead to that excess mineral build-up hard water can bring. Rainwater is friendly to plants and, conveniently, can be collected in rain barrels for use in your garden. If you don’t want to collect and use rainwater, the next best option for your garden is hard water.