Orchids need fertilizer to bloom. It's better to under-fertilize than over-fertilize. A common routine is to fertilize every 2 weeks in spring and summer, and once a month in the fall and winter. Orchid experts are constantly debating how to best fertilize. In the wild, roots and leaves absorb nutrients when rainwater washes plant and animal debris over them. Orchids in pots receive some nutrients as their potting media slowly breaks down, but this may not give them all they need.
- The easiest method to fertilize orchids is to use a balanced fertilizer in the spring, summer, and fall. "Balanced" means that the three numbers on the fertilizer are the same, or close to it, like 20-20-20. Follow the instructions on the label.
- Some growers prefer to give their orchids a high nitrogen fertilizer formula in the spring and summer, like 30-10-10. Then they switch to a low nitrogen formula, like 10-30-30, in the fall. Always follow the instructions on the label.
- If you do not have orchid food, regular plant food that is diluted is usually a good substitute. Only use 1/4 - 1/2 the recommended amount of regular plant food.
- Besides nitrogen, potassium, and phosphorus, orchids need small quantities of sulfur, magnesium, calcium, iron, manganese, zinc, copper, boron, chlorine, cobalt, and molybdenum. These are included in many fertilizers - check the label.