The importance of water for plants
Water is just as vital for plants as it is for humans. And so it also takes on functions similar to those in the human body: water is a solvent and transport medium for plants and ensures a balanced internal cell pressure. As a solvent and means of transport, it brings the nutrients from the soil that were taken up through the roots to where they are needed. It is evaporated again through the stomata of the leaves, creating a suction effect that draws new nutrients through the roots. The water pressure in the plant ensures that it can stand upright.
Water is therefore also a framework for plants. If the water pressure drops, the plant dries out and begins to wither.
Water plants properly
Different plants have different needs. Most houseplants need uniform soil moisture. In winter, plants should be watered less often and – nevertheless, regularly – because the lack of light slows down the metabolism. If the plants are rarely watered, but directly with a lot of water, the plant dies because its roots literally suffocate in the water. Yellow leaf tips or glassy leaves indicate it. Stale water is particularly suitable for watering plants. Carbon dioxide, which would lower the pH value, was able to escape and limescale settled on the ground. In addition, the water is at room temperature and the plants do not suffer from cold shock.
Importance of water hardness and pH when watering plants
The following facts about water make it clear how sensitive it is and how quickly its quality can be influenced: The components of water are two parts, hydrogen and oxygen. When a water molecule is formed, it is not yet connected to other substances and has a neutral pH value of 7. As soon as it combines with other substances, it changes the pH value. And wherever there is water, substances such as minerals, nutrients or chemicals are dissolved in it.
If you want to water your plants properly, you should know the amount of some of the solutes in tap water. The parameters calcium (calcium) and magnesium play a role. Together they determine the water hardness. The pH value changes with the hardness of the water. This in turn is decisive for the availability of nutrients. If the pH value is too low, i.e. the water is acidic, the phosphorus, potassium, calcium and magnesium are less available to the plant; If the value is too high to make the water too basic, there are problems with the absorption of nitrogen, iron, manganese and zinc.
Do not water plants with polluted water
Depending on which substances are dissolved in it, water can be a source of danger for plants. So you shouldn’t water them with water containing heavy metals. Uranium, cadmium or lead can impair the metabolism even in low concentrations.1 Heavy metals in water therefore cause stress for plants and they react accordingly. For example, they make more specific amino acids that inhibit growth. Zinc, manganese, copper and nickel cause a similar effect if they are present in too high doses. They are used by plants as trace elements in small quantities. Heavy metals can occur in drinking water due to corrosion in house pipes. You should not only have the water tested for the plants, but also for your own health. You can also have the water tested for pH and water hardness in order to know which fertilizers to add.