Temperature and Conditions for Orchids

Temperature

• Orchids can't survive frost, so they are typically grown as indoor plants except in tropical and subtropical climates that remain warm year-round. Most orchid varieties thrive when daytime temperatures remain between 70 and 75 degrees Fahrenheit and nighttime temperatures stay between 55 and 65 degrees. The preferred temperature range varies between the different orchid varieties. Phalaenopsis orchids prefer temperatures at the warmer end of the range while dendrobium varieties prefer the cooler end of the range.

Light

• Improper lighting reduces orchid blooms and can result in complete failure to flower. Provide the proper lighting conditions with natural or artificial light, as necessary. A southern window that receives bright light for most of the day supplies enough light for most orchids. Set the plants one to three feet from the window to prevent sun scorch on the foliage. Outdoors, orchids grow best in bright shaded locations. If natural light is unavailable, place the orchids beneath a fluorescent grow light for 12 hours daily.

Potting Mix

• Unlike most plants, orchids don't require potting soil. Orchids typically grow attached to tree trunks in nature. Use a potting mix formulated for orchids or epiphyte plants. Alternatively, create your own mix using soilless materials. Combine equal parts peat, tree fern fibers, charcoal and fir bark. These low-nutrient materials provide stability for the roots. Use a 30-10-10 orchid fertilizer or a 20-20-20 soluble fertilizer to supply nutrients to the plants, following the recommended application rates on the package.

Moisture

• Too much moisture causes the thick, fleshy roots of the orchid to rot or die, but the plants also can't tolerate completely dry conditions. Water the orchids when the soil dries slightly, or approximately once weekly while the plant is in bloom. After flowering, reduce watering so that the soil remains barely moist. Orchids also require humid conditions. Mist the plants with distilled water or set them on top of pebble and water filled trays to raise the humidity levels around the plants.