Nutrients are very important for all plants and living beings including orchid plants. Most plants obtain the nutrients and moisture they need from the soil. Soil or Terrestrial plants use their roots to absorb these nutrients. As most orchids are epiphytes that grow on the trees they can not benefit from the soil’s richness. Instead, they create their own mini nutrient gardens by trapping wind-blown plant and animal matter, grains of soil, mineral flakes, bird droppings and other nutrients between their tangled roots where they can be absorbed by the plant from the moisture around the roots. However this is not the only way orchids get their nutrients in their natural habitat, they rely on its relationship with other fungi or micro-organisms to assist them in their overall growth and health.
Photo: Orchids in their habitat
When we bring orchids to our home, the only source of nutrients for orchids is the irrigation water and the growing environment. Fertilizing your orchid regularly provides it with the nutrients it needs for optimal health, immunity and vigorous blooming. Unnurtured plants will be weak, less immune to pest and diseases, and wouldn’t give you a healthy or vigorous blooming plant.
What are the nutrients required for Orchid plants?
The nutrients that are required in larger amount are called macronutrients and the nutrients that are required in very small amount are called micronutrients or trace elements but they are still necessary to grow healthy plants. The macronutrients include Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulfur (S).
The micronutrients include boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), nickel (Ni) and chloride (Cl). Each one of these elements has their own role in aiding the plants in metabolism, reproduction, breakdown of carbohydrates, the formation of chlorophyll, production of sugar and carbohydrates etc.
You don’t need to worry about the first three ie Carbon, Hydrogen and Oxygen as they are available in the air and water. Other elements are known as fertilizer or mineral elements. The three letters ‘NPK’ that you see on the fertilizer packages represent nitrogen, phosphorus and potassium, and their percentage present in the fertilizer. Each of these fertilizer elements has multiple roles, in general nitrogen encourages strong leaf growth, phosphorus encourages flowering and budding, and potassium encourages stronger root growth.
The next two macronutrients, calcium, and magnesium are crucial for many cellular functions in plants, as well as fruit and flower formation. Be aware they might not always be present in your general NPK fertilizers, read your fertilizer contents to be sure. If you're growing orchids, make sure your fertilizer is a complete one, with both calcium and magnesium present. Speciality Bio 20 is a complete fertilizer except for calcium, which you may have to supplement once a month.
The last element is Sulfur. Generally, sulfur deficiency is very rare as in most fertilizers, the other nutrients are delivered in the form of sulfate salts, which automatically includes sulfur. If you are using NPK fertilizer like 20-20-20 or 19-19-19 without other elements mentioned above, you must supplement once a month with Calcium Nitrate, Magnesium Sulfate and other micronutrients or trace elements.