Seaweed Fertilizer for Orchids

Epiphyte Orchids

• Orchids are classified as either epiphytes, meaning that their roots take nutrients from rain and air, or terrestrials, which take nutrients from a soil medium. Epiphyte orchids adapted to growing high in trees in the rain forest, where they would get water from frequent rains, nutrients like nitrogen from the air and fertilizer from animal droppings. In the home, gardeners must provide nutrition in similar ways. Many orchid enthusiasts will dilute liquid seaweed fertilizer to one-fourth or one-fifth strength with water and fertilize with every watering to provide a constant level of nutrition. Orchid gardeners can water and fertilize either by misting leaves and roots or immersing the plant in the fertilizer. Epiphyte orchids will seldom need more fertilizer.

Terrestrial Orchids

• Terrestrial orchids grown in pots allow for more fertilizer options. They can be fertilized with diluted liquid seaweed-based organic fertilizers just like epiphyte orchids. Some orchid gardeners use a balanced 14-14-14 fertilizer that contains equal levels of nitrogen, phosphorus and potassium for a constant feed of nutrients. Organic versions of these balanced fertilizers may also contain seaweed, which provides nitrogen, and they are available in both liquid and time-release pellet form.

Extra Fertilizer

• Some terrestrial orchids may need an extra boost of nitrogen when they have been transplanted or stressed. Liquid seaweed and fish emulsion fertilizers are often used to give this extra boost of nutrients when orchids need it. When looking for an occasional fertilizer for an orchid growing in a potting medium, choose a 30-10-10 fertilizer with seaweed or fish emulsion to give the plant extra nitrogen.

Flushing

• If orchids are getting regular fertilization, they will also need to be flushed with clean, distilled water once a week to get rid of the buildup of minerals in most fertilizers. Gardeners can flush orchids mounted to bark by soaking the mount and roots in clean water. Potted orchids can be flushed by soaking or pouring clean water into a tray or by replacing the potting medium and rinsing the pot. Indications that a terrestrial orchid needs to be flushed include white mineral deposits on the pot.