One of the most common questions among plant caretakers is what is the best irrigation water. Although watering seems like a simple task, the type and quality of water we use can directly impact the health of our plants, altering their growth, flowering, and even the life of their substrate. Furthermore, choosing the wrong water can cause buildup of bacteria. Sales, problems of nutrients and general weakening. In this article, we explain in detail What water you should use to water each type of plant, how to prepare it correctly, and we answer the most frequently asked questions based on the most up-to-date and comprehensive information.
Why is water quality so important for irrigation?
Water is the main vehicle of the nutrients In plants. Inadequate water can leach harmful minerals, raise or lower the pH of the substrate, or even damage the roots due to excess Sales or chemicals. In nature, plants receive water from rain or subsoil, free of additives and with balanced mineralization. By reproducing this type of water in our homes or gardens, we ensure that plants grow strong, healthy, and more resistant to pests and diseases.
Types of water for watering plants and their characteristics
Not all water is the same, nor is it suitable for every plant. Below, we detail the most commonly used types of water for domestic and professional irrigation, highlighting their advantages, disadvantages, and the plants recommended for each.
- Rain water: It is the most natural, balanced, and beneficial option for plants. Its pH is usually around neutral (7,0) and it is free of additives. It is perfect for all types of plants, especially acidophilic, carnivorous, and species sensitive to lime or chlorine. If you have the opportunity, collect and store it in clean containers, away from contaminated areas, and use it as soon as possible to avoid buildup of bacteria or dust.
- Distilled water: It is obtained by distillation, eliminating impurities, chlorine and minerals. It is highly pure and highly recommended for carnivorous plants, orchids, ferns, and demanding species. Its lack of minerals can be a disadvantage in crops that require specific nutrientsIn these cases, it is advisable to supplement with formulated fertilizers.
- Reverse osmosis water: This system filters water to remove salts, chlorine, and contaminants. The result is similar to distilled water, but sometimes retains traces of beneficial minerals. It's ideal for delicate plants, bonsai, and aquarium plants, but can also be used mixed with tap water for less demanding species.
- Air conditioning water: It comes from condensation and is practically distilled, so it is free of salts and chemicals. It is recommended for irrigation. carnivorous or clean leaves, but it's not suitable as the sole remedy for plants that need minerals. Always let it reach room temperature before using it.
- Tap water: It is the most accessible, but its composition varies by region. It usually contains chlorine, calcium, fluoride, and other additives that can harm sensitive species such as hydrangeas, gardenias, azaleas, or calatheas. If you must use it, let it sit for 12-24 hours to allow the chlorine to evaporate, and if possible, add a few drops of vinegar or lemon juice to lower the pH if your plant needs it.
- Bottled mineral water: It's suitable for occasional watering, especially for indoor plants, but the high dissolved salt content of some brands can be excessive over time. Always choose low-mineralization water and check the label.
- Filtered water: This tap water is treated with household filters or purifying jugs, useful for removing chlorine and some salts, bringing it closer to the quality of rainwater. It's also advisable to reuse water from dehumidifiers, ensuring the tank is clean.
- River or well water: May contain contaminants, pesticides, or excess salts depending on the environment. Preliminary analysis is required, and if in doubt, filtration and pH and EC (conductivity) adjustment are required. Use only if you know the composition.
Hard Water vs. Soft Water: Differences and How They Affect Plants
Water can be classified as hard or soft depending on its water content. Mineral salts, mainly calcium and magnesium. Hard water leaves limescale residues in pots and leaves, it makes it difficult to absorb nutrients and alters the pH of the substrate, harming most ornamental and acidophilic species. Soft water, containing less salt, is better tolerated by most plants, although its lack of minerals may require supplemental fertilizer.
To find out if your water is hard, you can observe the formation of white scale on faucets or flower pot trays, or test it using test strips or in a laboratory. If it's very hard, choose to mix it with distilled or reverse osmosis water and monitor the pH regularly.
Which plants are most sensitive to the type of water?
Some species are particularly sensitive to irrigation water. It's essential to avoid tap or hard water for plants such as:
- Hydrangeas, gardenias, azaleas
- Calatheas, ferns, orchids
- Carnivorous plants (Dionaea, Sarracenia)
On the other hand, other plants tolerate less pure water better, such as sansevieria, ficus, monstera deliciosa, and some succulents and cacti. Although it is always preferable to use better quality water, especially during critical periods such as flowering o rooting.
Practical tips for preparing and adjusting irrigation water
- Let the tap water rest reduces the amount of chlorine and other volatile compounds. Use at room temperature.
- To lower the pH, add a few drops of vinegar or lemon juice. To raise it, you can use baking soda in very small doses.
- Mixing different types of water (e.g. distilled and tap) allows you to adjust the mineralization.
- Collect rainwater whenever possible and keep it in clean containers, protected from direct light.
When and how to water your plants correctly?
In addition to the type of water, the timing and method of watering are essential:
- Water when the substrate is dry on the surface, checking with a wooden stick or weighing the pot after watering.
- Avoid overhead watering of plants prone to fungal diseases.
- Adapt the frequency according to the season and the needs of each species.
- Prefer drip irrigation or automatic systems for save water and avoid water stress.
If you're interested in more efficient irrigation, you can build your own homemade drip irrigation system, optimizing water consumption and plant health.
The type of irrigation water you use can make the difference between vigorous, vibrant plants or diseased plants with growth problems. Choosing rainwater, distilled water, or reverse osmosis water, or, failing that, treating or blending tap water, will allow you to keep your garden or indoor collection at its best, always adapting your selection to the specific species and the conditions in your area.
