We all know that plants require air, water, light, space and soil to grow and reproduce. However, many gardeners claim that milk or Coke can also help in growing certain plants. Science on the effects of these materials is slight, but each of these substances seems to have some merits as well as drawbacks on the growth of the plant.
Water is a source of dissolved nutrients from the soil. This is greatly required for plant survival and growth, as without it the plant will not be able to absorb the necessary nutrition from the soil. Water is also required by plants to complete the natural process of photosynthesis, along with proper light. Moreover, it helps in hydration of the leaves of the plant and gives it protection from drying out.
The protein and fats contained in milk make it difficult for plants to absorb water. However, milk contains enzymes and fungicidal properties that may restrain growth of mould and bacteria. When diluted with water, it may help to fight various diseases including fungi that may harm the plant's growth. Moreover, calcium contained in the milk can help build the plant cell walls that allow easy transportation of nutrients and also control the pH level of the soil. If you decide to try feeding milk to plants, gardeners recommend diluting it with plain water.
The sugar content in Coke can create a concentrated solution that may damage the root cells, resulting in their losing the ability to take in water, causing the plant to die of thirst. Plants do not need to take in extra sugar, as the process of photosynthesis allows plants to make their own sugar for energy. The excessive sugar concentration in Coke can also promote bacteria and mould growth.
A plant will grow bigger and thrive better in water. The only reason why a plant would be able to grow when fed Coke is because it contains some amount of water. In small quantities, milk may be beneficial to plant growth. However, milk should never be used as a substitute for water. Water is essential for plant growth.