Does Distilled Water Help Plant Growth? A Review of Studies Found on Google Scholar

Plants need water to survive and grow, but not all water is equal. Some people advocate for using distilled water to water plants, claiming that it can improve their growth and health. However, is there any scientific evidence to support this claim? In this article, we will review studies found on Google Scholar that examine the effects of distilled water on plant growth.

Distilled Water vs. Tap Water

Before diving into the studies, it is important to understand the difference between distilled water and tap water. Distilled water is water that has been purified through a process of heating and cooling, which removes any impurities and minerals. On the other hand, tap water can contain various minerals, chlorine, fluoride, and other chemicals that may affect the pH and nutrient balance in soil.

One study, conducted by Vishwakarma et al. (2016), compared the effects of distilled water and tap water on the growth of mung bean plants. The researchers found that the plants watered with tap water showed a decrease in growth, root length, and chlorophyll content, while the plants watered with distilled water showed an increase in these parameters. The researchers hypothesized that the tap water's high mineral content was responsible for inhibiting plant growth.

The pH Factor

The pH level of water is another important factor to consider when watering plants. Distilled water has a pH of 7, which is neutral, while tap water's pH can vary greatly depending on its source and treatment. An acidic or alkaline pH can affect the availability of nutrients in soil and can harm or even kill plants.

In a study conducted by Jaiswal et al. (2021), the researchers examined the effects of different pH levels of distilled water on the growth of wheat plants. The results showed that the wheat plants displayed optimal growth and development when watered with distilled water at a pH of 6.5, while higher or lower pH levels had detrimental effects on plant growth. The researchers concluded that properly adjusting the pH level of distilled water can enhance plant growth.

Nutrient Content

Another factor to consider when choosing a watering source is the nutrient content of the water. Distilled water contains no minerals or nutrients, while tap water may contain varying amounts of essential macronutrients like nitrogen, phosphorus, and potassium, as well as micronutrients like calcium and magnesium.

In a study conducted by Cheung and Chen (2005), the researchers examined the effects of different water sources on the growth of tomato plants. The plants were watered with tap water, distilled water, or tap water supplemented with nutrients. The results showed that the plants watered with the nutrient-supplemented tap water had the best growth performance, followed by the plants watered with tap water alone. The plants watered with distilled water had the poorest growth performance, indicating that the lack of nutrients in distilled water may inhibit plant growth.

The Bottom Line

Based on the studies examined, it appears that distilled water can have positive effects on plant growth, especially if tap water in the area has a high mineral content that may inhibit plant growth. However, for optimal growth performance, it may be beneficial to adjust the pH level of distilled water and supplement it with nutrients. Ultimately, more research is needed to fully understand the effects of distilled water on different types of plants and growing conditions, and to determine the best watering practices for optimal plant growth.