The right balance of light is critical to getting orchid plants to bloom, as well as making the plant feel at home with appropriate amount of air circulation, humidity, water and fertilizer. These tropicals are accustomed to hanging from trees and using planting mediums only as a means to stay upright. With 20,000 different species, orchids are often categorized by light needs, whether low, medium or high, when grown indoors as houseplants.
Determine if your orchid is getting enough light. Leaves should be light, bright green. If deep green, it needs more light. If leaves are yellowing, it needs less light.
Augment natural light with artificial light. This may range from simple fluorescent grow lights to high intensity discharge plant grow lights that produce 500 percent more light than standard grow lights.
Provide air circulation with a small fan or open windows.
Keep your orchid on a humidity tray; never allow it to stand in water.
Water as needed. Roots should be white, firm and fleshy. If roots become soft, dark and mushy you are overwatering. When in doubt, it is better to underwater an orchid.
Use a blossom booster fertilizer high in phosphorus and low in nitrogen in the autumn when orchids start setting their buds. A good recommendation is 10-30-20 applied at half-strength every week for six weeks. Use a balanced fertilizer diluted to half-strength once a week at all other times.
Flush pots with water at least once a year to avoid salt build up that may burn the orchid's roots.