Answer: Among the easiest to care for as houseplants are species and named cultivars of Phalaenopsis (known as moth orchids) and Paphiopedilum (known as ladyslippers. All orchids need good light, but they cannot stand much of the heat which usually accompanies high light intensities. You may reduce temperatures in south or west-facing summer windows by drawing sheer curtains across them.
Many people grow their orchids successfully under fluorescent tubes. Place them so the lights are about eight inches above the orchids' foliage, and keep the lights on from twelve to fourteen hours daily.
Orchids may fail to bloom if night temperatures are very close to daytime levels. A two-week period in spring or fall where temperatures at night are kept ten to fifteen degrees cooler than during the day should initiate flower development, assuming the plant receives adequate light levels.
While neither Phalaenopsis nor Paphiopedilum orchids need extremely high humidity, they do benefit from added humidity in winter. Placing pots on top of gravel in moisture-filled trays might help. You just need to be careful that their pots are set above the water line so no moisture will be drawn in through bottom drain holes. Room humidifiers also help increase relative humidity without jeopardizing orchid roots.
Neither of these orchids should be allowed to dry out completely between waterings. How often you water will depend on how bright their growing conditions, how humid, and how warm it is, all factors that impact how fast the potting mix will dry. Always use room temperature or barely lukewarm water that will not shock the orchids' roots, and avoid softened water if at all possible.
Make a point of holding the container over a sink or washtub and watering thoroughly so moisture drips right through and is discarded. Lift the pot right after you've watered to get a feeling for its weight, then hold off watering again until it feels lighter. Don't rely on the calendar to tell you when to water.
Use a special orchid fertilizer such as 30-10-10, mixed half-strength, once a month - more often during growth spurts in spring and summer. Every three months fertilize them with a complete fertilizer containing minor elements along with the major elements, nitrogen, phosphorus, and potassium. Almost any ratio of the major elements in this complete fertilizer is acceptable.
Best wishes with your new orchid!
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