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Apart from sunlight and air, water is one of the key things that all plants need to survive. Any good plant parent knows the importance of watering plants well. However, the watering regime is not the only thing to consider. You must also think about the kind of water you are giving your plants.
Distilled water has been purified to remove all the dissolved minerals and toxins. Distilled water is, therefore, good for plants that are sensitive to chemicals like chlorine and fluoride that are often found in tap water. Potted plants especially benefit from being watered with distilled water.
It is not strictly necessary to water all plants with distilled water. Doing so would be very expensive unless you plan on making large quantities of distilled water yourself. This article discusses why distilled water is good for plants, which plants benefit from it the most, and how to distill water for your plants at home.
What Is Distilled Water?
Purified water, filtered water, mineral water, spring water, tap water – there are so many different types of water! What exactly is distilled water? Is it that different from other kinds of water?
Distillation refers to the process of separating a liquid into all its component parts by evaporating and condensing it.
To produce distilled water, regular tap water, rainwater, or spring water is heated to a boil. As it evaporates, organic and inorganic chemicals, heavy metals, and pathogens are left behind.
The steam is trapped and condensed back into liquid form. The resulting liquid is pure, distilled H2O.
Spring water, mineral water, and filtered water still contain healthy levels of dissolved minerals, but they have been purified of all toxins and microbes.
Distilled water, on the other hand, contains absolutely no dissolved minerals or chemicals. It is water in its purest form.
Can You Water Plants With Distilled Water?
Tap water in cities is notorious for the chemicals and toxins it contains. Not every city’s tap water is contaminated, but sadly most are.
Tests done on tap water in urban areas have revealed that it can contain high levels of chlorine and fluorine, toxins like arsenic and pesticides, as well as heavy metals like lead and mercury.
Therefore, many urban plant parents look for alternative sources of water for their plants. Many people water their plants with distilled water.
There is a common misconception that distilled water is neither safe to drink nor to give to plants because it leaches nutrients from organisms’ cells. However, no scientific evidence currently supports this.
It is perfectly safe to give plants distilled water. Often it is better to give plants distilled water than tap water or even rainwater (depending on where you live).
What Are The Benefits Of Distilled Water For Plants?
Distilled water is not beneficial to plants because it contains any special substance that helps plants grow. Rather, it is beneficial because of what it doesn’t contain.
The primary benefit of watering plants with distilled water is that you are not exposing them to any viruses, bacteria, parasites, heavy metals, strong chemicals, or any other contaminants.
If plants are watered with distilled water, there is no risk of mineral salts building up in the soil. Such salts can draw water from plants’ roots, resulting in yellow leaves and stunted growth.
Indoor plants growing in pots and containers are most susceptible to mineral salt build-up in their soil because their roots are only growing in a small quantity of soil, and rain cannot flush out the soil.
Do Plants Grow Better With Distilled Water?
Some plants are more sensitive to chemicals and heavy metals than others. These plants generally grow better if they are given distilled water instead of tap water.
For example, dracaenas are extremely sensitive to fluoride. Fluoride is commonly added to tap water to help manage tooth decay amongst urban populations. Therefore, dracaenas that are watered with distilled water are much healthier and happier than those that are watered with tap water.
However, not all plants grow better with distilled water. Remember, distilled water contains absolutely no dissolved minerals, even beneficial ones. Plants need certain levels of phosphorus, potassium, magnesium, calcium, and zinc (amongst others) to thrive.
Some studies indicate that plants watered with tap water grow faster and larger than plants that are only given distilled water. Other studies show that plants watered with distilled water grow better than plants that are given tap water.
Ultimately, it depends on the species of plant in question and how contaminated the tap water in your city is.
Is Distilled Water Necessary For Plants?
Distilled water is certainly not a necessity for all plants. Plants growing outside in the garden do not need to be watered with distilled water.
Although houseplants benefit the most from distilled water, even they do not strictly need it. Most houseplants are perfectly fine being watered with rain water or even tap water.
Which Plants Need Distilled Water?
There are certain plants that are extremely sensitive to high levels of chemicals and minerals. These plants should ideally be watered with distilled water.
The following species need distilled water:
- Venus fly traps
- Air plants
- Peace lilies
- Boston ferns
Can Distilled Water Cause Plant Nutrient Deficiencies?
Even though distilled water is highly beneficial for some plants, in the long run, it can be detrimental to a plant’s health. You cannot only water plants with distilled water because plants need more than just H2O to survive.
Calcium, magnesium, and zinc are just some of the micronutrients that plants require to grow, flower, and fruit. These minerals are found in tap water, rainwater, and bottled spring water but not in distilled water.
If plants are only ever given distilled water and no other types of water, it can result in plants developing nutrient deficiencies. The leaves may turn yellow, their growth rate may slow down, and they may not flower as prolifically.
Another way that distilled water can cause plant nutrient deficiencies is by altering the pH of the soil. Certain plants require slightly acidic or ericaceous soil, while other plants prefer growing in alkaline soil.
Distilled water has a pH of precisely 7.0 – it is completely neutral. Therefore, it can increase the pH of acidic soil and decrease the pH of alkaline soil.
Plants need a particular soil pH to effectively absorb nutrients from the soil. If a plant is growing in soil with the wrong pH, it is likely to develop a nutrient deficiency.
Tips For Watering Plants With Distilled Water
Now that you know more about what distilled water is and how it can benefit certain plants, here are some things to remember if you want to give your plants distilled water:
- Be sure to fertilize plants regularly. Distilled water contains no nutrients, so you need to add nutrients by using an organic, water-soluble fertilizer.
- Consider the pH that certain plants require. If you water a plant that needs slightly acidic conditions with distilled water, be sure to add some ericaceous compost to the soil. Or, if you have a plant that likes alkaline conditions, add some dolomitic lime to the soil to increase the pH slightly.
- Use a combination of rainwater, spring or river water, and distilled water. The vast majority of plants do not need to be given distilled water exclusively. By watering with a few different kinds of water, you can reduce the cost of watering your plants while still giving them the benefits of distilled water.
How To Make Distilled Water At Home
Distilled water is readily available because it is often used for mixing baby formula or certain medicines. You can buy it online or from your local grocery store or pharmacy.
However, you can only buy distilled water in small quantities, and it costs around $15 per gallon. If you have many plants, the cost can add up very quickly! Therefore, it is better to make your own distilled water at home.
You do not need any fancy laboratory equipment. You can probably find everything you need to make distilled water in your kitchen.
To make distilled water, you need the following:
- A big metal pot with a lid
- A heat-resistant glass bowl that fits inside the pot
- Ice cubes
- Tap water
When you have gathered all the equipment and materials, follow these steps to make distilled water:
- Fill the pot with tap water. It should be approximately half full.
- Place the glass bowl inside the pot so that it floats in the water.
- Put the pot on the stove and turn up the heat. Let the water reach a boil.
- Once the water is boiling, flip the pot’s lid upside down and put it on the pot.
- Fill the lid with ice cubes. The ice is meant to cool the steam down as it hits the lid, causing it to condense and drip into the glass bowl.
- Keep an eye on the boiling water and top it up to half full when the water level gets low. The distillation process takes a surprising amount of time, so you must be patient! Expect it to take around 12 to 13 hours to make a gallon of distilled water.
- Once you have the desired amount of distilled water, throw the remaining water in the pot out. Do not drink it or water garden plants with it because it contains concentrated levels of toxins and chemicals.
Cheaper Alternatives To Distilled Water For Plants
Even if you make your own distilled water at home, the process is still hugely expensive and time-consuming. There will be a significant spike in your electricity bill if you regularly have a pot of water boiling on the stove for upwards of 12 hours!
Luckily, there are many good alternatives to distilled water for watering plants. You do not need to distill water to get rid of most of the harmful chemicals.
Many people water their plants with tap water, but they leave the water in a bucket for a day before giving it to their plants. Chemicals like chlorine and fluorine will naturally dissipate when given enough time.
If you live near an unpolluted lake or river, you can collect water for your plants. This is only really practical in more rural areas.
Another great, low-cost source of water for your plants is rainwater. Put a bucket out during rain showers to collect water for your indoor plants. Like distilled water, rainwater does not contain any chemicals or minerals that can build up in the soil as salts.
Rainwater Is Not Always Safe For Plants!
You must be careful about watering your plants with rainwater if you live in a large, metropolitan city with high levels of air pollution. Nitrogen oxides and sulfates in polluted air can combine with airborne water molecules. This is what causes acid rain.
Studies have also shown that toxins like formaldehyde and benzene can be carried down from the atmosphere during heavy rainstorms. For example, this happened in Los Angeles during the late 1990s.
How you collect rainwater is also important. Rainwater that flows off your roof can be contaminated with bacteria and pathogens from bird poop.
Dust, pollen, soot, and airborne chemicals also settle on our rooves. When it rains, the water washes these particles from the roof. This rainwater runoff is, therefore, contaminated.
Your roof may be constructed from materials that can contaminate rainwater runoff, like asphalt, asbestos, copper, or lead. Be sure to find out what your roof is made of before collecting rainwater runoff for your plants!
Because distilled water is free from chemicals, heavy metals, toxins, bacteria, and pathogens, it is good for watering plants. It prevents mineral salts from building up in the soil, especially in potted plants.
Watering all your plants with distilled water is far from necessary. Only water plants that are very sensitive to chemicals like chlorine and fluorine with distilled water.