The amount of fertilizer you give your orchid plants and the time of year that you should apply depends on the type of orchid that you are growing. It is important that you give more fertilizer during the times when the flower is blooming and less when it is not. Here are a few methods of applying fertilizer and the reasons behind them.
More is Better
Fertilize only once per month with full-strength commercial fertilizer that will give nutrients to the orchids. After that, flush them with pure, fresh water once a week. The idea behind this procedure is that you will give the maximum amount of nutrients in one shot ,and the next few weeks of pure water baths will wash away any unwanted salts that might eventually harm the roots.
Less is more
Other orchid farmers have tried a process that delivers less fertilizer on a more frequent basis, which is also an effective option. Take the same amount of recommended fertilizer that would normally be used once a month and dilute it with water into fourths to be used once per week instead. These farmers have found that the weaker solution delivered more frequently has had a huge impact on their orchids success. There is less of a shock to the roots systems and blooms have produced more intensely and more regularly.
Whether you choose to fertilize all at once or in a diluted fashion, it is important to make sure that your orchids are properly fertilized during the summer months when most likely they are dormant. Continuing to water the roots and bark once a week is crucial while new growths begin to mature. During the final summer months when these buds are almost ready to sprout, fertilize every week rather than every other. Make sure that the bark stays continuously moist as well. If you notice dry soil, moisten as necessary.
The down season
When the orchids are not preparing to bloom and are essentially dormant, it is not necessary to apply the same amount of fertilizer on a regular basis. At this point, fertilizing once every 15 days is sufficient for sustaining proper nutrients. Keeping them watered every other week is enough to insure that they will have new blooms in the next season. If you notice any browning of leaves during this time, it is perfectly okay to add a diluted mixture to the soil just in case. Also, adding more crushed eggshells or even leftover, crushed seafood shells will also help produce green leaves during seasons when the flowers do not bloom.
Regardless of season, and regardless of species, your orchids will need constant care and a healthy supply of nutrients. Remember: orchids that bloom in the winter only need continuous fertilization during blooming season, while summer bloomers need a consistent feeding throughout the year.