Orchids are among the most prolific, adaptable and coveted species of flowering plants in the world. Over 28,000 species of orchids exist, and thrive in a myriad of diverse growing conditions including rainforests, Arctic tundra regions, grassy plains, swamps, mountain areas and deserts. Home gardeners can choose from a wide variety of orchids. Despite their difficult-to-grow reputation, many orchids are as easy to care for as any other houseplant.
Garden soil or top soil retains more water than an orchid needs, leaving the plant susceptible to disease. Choose a potting media that allows air to freely circulate around the orchid's roots and provides support for the plant. Use Sphagnum moss, perlite, coconut fiber, peat moss, or other commercially available orchid potting mix.
Sufficient light is required for orchids to grow well. Place orchids near a south-facing window indoors so the plant can receive daily bright, indirect light in the morning and through the afternoon. Place outdoor orchids in partially shaded conditions. Too much light can rob chlorophyll from fragile orchid leaves, causing them to wither and brown.
Temperature & Humidity
Most orchids grow well in temperatures between 50 to 90 degrees F. Shield orchids from temperatures lower than 50 degrees or higher than 110 degrees to prevent damage to plants. Homes with other healthy houseplants generally have adequate humidity levels--40 to 60 percent--for growing orchids. However, indoor heating units can lower the humidity in the winter, so mist leaves with a sprayer or use a humidifier to ensure the plants continue to thrive.
Orchids are not typically heavy feeders. Fertilize orchids with a water soluble fertilizer at half the recommended rate no more than once a month. Prevent the accumulation of salts in fertilizers from harming the orchids by occasionally flushing or dousing the potting media with several cups of water, then allow to drain thoroughly.
Watering & Dehydration
Some orchids require more watering than others depending upon their growth cycle, roots and potting media. Water plants with thin fragile leaves more than those with thicker more succulent foliage. Orchids can dehydrate if not watered regularly, causing foliage to wither and yellow. However, far more orchids die from over watering so never allow plants to sit directly in water.