There are many different types of water. Each of them interacts and affects humans, as well as plants, in different ways.
For some plants that are rather tricky to care for, it may be a better choice to use distilled water or rainwater instead of the often used tap water.
Your choice of water can help your house plant grow to its full potential and avoid future issues like rotting or fungal diseases.
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What is the Best Water for Houseplants?
Rainwater or distilled water are considered to be the best choices for watering houseplants. The quality of tap water often depends on where you live and some plants are sensitive to the minerals or chemicals added to it. Rainwater has the advantage of containing high oxygen levels and minerals whereas distilled water is completely free of any toxins.
The Impact of Water on Plants
Understanding the different characteristics of water will help you make better choices for your plants along the way.
Hard water can cause limescale deposition on pipes and appliances. It has many minerals in it, which include minerals such as calcium, magnesium carbonates, bicarbonates, and sulfites.
These different minerals can lead calcium and magnesium salts to accumulate on top of the soil, within the soil, or on the sides of your plant’s pot.
These salts are usually harmless but can build up in the soil. As time progresses they can impact the nutrients and the pH of the soil, causing damage to your plant,
The best way to protect your plant in hard water areas is by flushing out salt from the soil regularly with rainwater, distilled water, or bottled water.
The amount of sodium present in different types of water can vary greatly, and many plants are unable to survive in water that has high sodium.
Tap water is suitable for watering plants in most places as it contains decent levels of sodium, but using water softeners can cause major issues when watering your plants.
Water softeners replace calcium and magnesium ions in hard water with potassium or sodium ions. However, this will reduce limescale from building up on your pipes and makes water drinkable for humans, but it will severely damage your plants due to high sodium ions.
Never water your plants if you use water softeners as the majority of houseplants hate high levels of salt in their water; as an alternative, use filtered water, distilled water, or bottled water.
The delivery of oxygen to the roots is an essential part of your plant’s growth. Plants need to be planted in well-aerated and less soggy soils where they have access to oxygen.
Several pieces of research have shown that high oxygen content in water leads to larger root mass, causing faster intake of nutrients, making your plants grow more vigorously.
Cool water contains higher oxygen content compared to warm water, and any water containing more oxygen content has fewer dissolved minerals in it.
Rainwater is known to have the highest levels of oxygen compared to any other form of water.
However, choosing well-aerated soil and following a proper watering schedule will help to fix this issue.
Chlorine or chloramine present in some types of water can be dangerous for the root of your plants. It can kill off the good bacteria and other soil micro-organisms present within the root zone.
Chlorine can also be toxic for some houseplants, and cause brown tips and brown spots on the leaves.
Types of Water for Houseplants
Depending on the mineral content present in tap water, it can be considered hard or soft. The only water that is soft naturally is rainwater as it contains few minerals.
Once rainwater falls to the ground, it picks up minerals such as calcium and magnesium from underground water resources, and it becomes hard.
This hard water can then be made soft again by using water softeners that add potassium and sodium ions to remove calcium and magnesium.
Pros of tap water
- The majority of people have free tap water, or it costs much less than other available water sources.
- Water quality is set to meet a specific standard allowing the user to know what the water contains.
Cons of tap water
- In some places, tap water contains chlorine and fluoride in high amounts.
- Calcium and magnesium ions present in hard water build-up salt on top of the soil, which repels water.
- If the tap water is soft, then the high sodium levels can cause sodium toxicity, which affects the pH of the soil.
Many homes have bottled water available that is bought in stores and often times it is also used to water houseplants.
Underground water sources eventually make their way to the surface of the earth’s soil, and it is then collected into bottles.
The amount of natural minerals present in the water determines whether the bottled water would be labeled as spring water or mineral water.
Pros of bottled/spring water
- Bottled water can contain a good amount of minerals such as calcium and magnesium.
- They do not contain contaminants such as chlorine and fluoride.
Cone of bottled/spring water
- Buying bottled/spring water can be expensive.
- Bottled/spring water comes in plastic packaging, which causes pollution.
Distilled water is free from contaminant and impurities as it goes through a process which makes it highly purified. Water is turned to steam by boiling and then condensed back into a liquid.
Pros of distilled water
- Distilled water is free from harmful chemicals and minerals such as calcium, magnesium, and sodium.
- Using distilled water will prevent the build-up of substances on the top of the soil, which can affect water infiltration.
Cons of distilled water
- Distillation removes high amounts of minerals that are needed for plant growth, such as calcium and magnesium.
- Distilled water is expensive because of the manufacturing process.
Rainwater is the natural water you receive from the sky. This water is soft but still high in minerals and is good for plants.
Pros of rainwater
- Rainwater is free to use by anyone.
- Rainwater contains the perfect amount of minerals needed for plant growth, with few amounts of harmful chemicals in it.
Cons of rainwater
- Rainwater may be not available all year round depending on your location
- Rainwater collected in areas where manufacturing occurs can be highly acid due to pollution.
Frequently Asked Questions About The Best Water For Houseplants
Can I use tap water even if I use a water softener to water plants?
Using tap water that has passed through a water softener is discouraged, but this does not mean you cannot use it. This type of water will contain more sodium ions, which can cause sodium toxicity or form salt crusts on top of the soil.
Will my plant grow better with tap water or distilled water?
The majority of experts believe that using distilled water helps plants grow faster and stronger when compared to tap water. Plant watered with distilled water also produces more leaves. However, make sure to add in additional nutrients through fertilizers as distilled water if free of necessary minerals.
How long should I let the tap water sit before watering my plants?
You should let tap water sit for twenty-four hours before watering your plants with it. This will allow the chlorine and fluoride to dissipate.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.