Plan the perfect garden with our interactive tool →

How to Use Soft Water to Water Plants

Soft water is not ideal for watering plants. Not only does it lack the nutritious minerals of harder waters, but it actually leaches nutrients out of the soil. However, if soft water is your only option, it is possible to safely water your plants with it. By paying careful attention to the soil's nutrient content, you can avoid many of the common problems that arise in plants watered with soft water.

Know which plants to water with soft water. Soft water is slightly acidic, and should only be used to water plants that like acidic soil like blueberries, azaleas, rhododendrons, camellias, tomatoes, roses and bearded irises.

Keep the soil nourished by testing its mineral content with a TDS meter at least once a month. Mix a sample of your soil with water (the amount will be dictated by the manufacturer's instructions) and insert the TDS meter which will give you a reading which will reveal the mineral content of your soil. Soft water can leach important minerals like calcium and magnesium carbonates out of the soil. Replace these or any other missing nutrients with a foliar spray or water-soluble fertilizer.

Dilute soft water with an equal amount of rainwater or sparkling mineral water if your plants' soil is continually nutrient deficient.

Do not use softened water that has been chemically softened by a water softener to water your plants. Water softeners work by adding sodium and potassium chloride to the water which can slow your plants' growth and kill your lawn.

Water Your Plants Twice A Day?

While most plants prefer evenly moist soil, some plants such as jade plant (Crassula argentea), which is typically grown as a houseplant, or summered outside during frost-free months, prefers drier soil Jade in thrives as a perennial in U.S. Department of Agriculture plant hardiness zones 10 and 11. As a rule, most plants prefer 1 to 2 inches of natural rainfall a week. This is because water leaches quickly through the bottom of the pot with each watering, the soil heats and dries quickly in summer sun and plants experiencing rapid growth may use the available water quickly. If the soil in your containers dries during the day, you may need to water them twice a day. The amount of water your plants need changes as they grow. The type of soil in your containers and plant pots also affects how quickly it dries. Using this mixture reduces the need for frequent watering and may allow you to water your plants once a day or less often.

Garden Guides