Orchids are a large family of beautiful, tropical flowers. They come in a tremendous range of colors, sizes and shapes. Some are fragrant, even smelling like chocolate or coconut. Orchid fanciers wax poetic over the delicate beauty of these unusual flowers, but they do have a reputation as difficult to grow. Orchids have specific needs for fertilizer. While it is easiest to buy orchid food at the nursery, it is satisfying and cost-effective to make your own.
In their native habitats, orchids get nutrients from the air, water and whatever is nearby. Grown at home, it is up to you to provide the necessary nutrients for healthy growth and optimal flowering. Orchids require a proper balance of nitrogen, phosphorus and potassium, along with trace elements. Nitrogen promotes healthy stems and foliage, phosphorus makes roots strong and potassium promotes healthy flowers. These three nutrients are macronutrients. Trace elements include iron, zinc, copper and boron.
A good source of vitamins such as niacin, thiamin, riboflavin and folic acid necessary for healthy orchid growth is water used for boiling rice. The Care for Your Orchids website recommends using brown rice rather than white. It's an easy fertilizer to make -- after cooking rice, let the leftover water cool, then water the orchid. Make the rice water a more balanced fertilizer by dissolving Epsom salt, which contains magnesium, or molasses, a good source of potassium, into the water before use.
Dried eggshells are good source of calcium and other nutrients. Crush eggshells, then boil them in a large pot of water. Once the water reaches the boiling point, turn off the heat and allow the eggshells to steep for up to eight hours. You can discard the shells, and pour the water into a spray bottle for easy use. Just spray onto the bark around the orchids. Alternatively, you can just grind up eggshells and sprinkle around the plant. This is not as effective a method, however.
Potatoes provide potassium and a small amount of phosphorus, both essential for healthy orchid growth and flowering. Dice the potatoes into very small chunks, leaving on the skin. For even more potassium, you can add small pieces of banana. Boil this mixture for several minutes, and allow it to reach room temperature before use. For better nutrient balance, add 1 tsp. of Epsom salt, which will add magnesium. Use this mixture to water your orchids as usual.