What Do Orchids Eat?

Basic Fertilizer

• "Weakly, weekly" is a rule of thumb for feeding orchid plants. Orchids do need fertilizer, but it is possible to burn them. The American Orchid Society recommends frequent, dilute watering with fertilizer. Use a regular 20-20-20 balanced plant fertilizer, but dilute it to one-quarter strength. Water the plants with the dilute fertilizer at least weekly when they are producing blooms. Every fourth week, just use plain water to protect the orchids from accidental over-fertilization. Specific orchid fertilizers may be used at full strength; follow the manufacturer's instructions exactly for mixing and applying.

Air Orchids

• Orchids that live in the air, epiphytes, are commonly found in the canopy level of the rainforest in the wild and will thrive in a subtropical backyard, given enough moisture. These orchids send out a highly developed network of stem-like roots that form a web to capture and absorb rain and moisture from the air. They are capable of storing water between rainfalls, and efficiently draw nutrients like nitrogen, phosphorus and iron from rain and airborne dust. Nutrient particles that fall on the roots contain decaying matter from insects and other organic content.

Cautions

• If an orchid plant gets dried out, do not feed it until you have restored its hydration. Water the plant and give it time to absorb the water. Then water with dilute fertilizer; use a very light mix until you are sure the plant is fully hydrated and you won't risk burning dry roots. If your orchid is planted in bark, it needs more nitrogen than orchids in other potting media. Use a nitrogen-heavy fertilizer mix -- a 20-10-10 or a 30-10-10 -- and dilute it to 3 parts water, 1 part fertilizer before applying. (Commercial fertilizers are made of nitrogen, potassium and phosphorus; the first number tells the proportion of nitrogen in the mix.)

Carnivorous Orchids?

• Orchids do not eat insects. Some species, like the Lady Slipper orchids, have a tubular shape that resembles the cup-like traps of insect- and small amphibian-eating carnivorous plants. Orchids use their unusual shapes to attract insects and release pollen on them. Insects like bees that crawl around the orchid's cavities receive a generous dusting of pollen that then rubs off on the next orchid they visit. But they are in no danger of becoming lunch to a voracious plant; orchids are not carnivores.